Capcom has released a list of the changes to each character in Super Street Fighter II HD Remix OMGWTFBBQ. Of course if you're not happy with the list, you can go back to Original mode which plays like what we're all used to.
I'm going to say it before you get down into the list, the Zangief changes are huge and I'm not sure I like them (easier SPD?). Also Akuma now has a super meter and has the Raging Demon. I'm going to give this thing a try though, some of the changes sound good (such as Vega able to cancel a wall attack).
The list, as posted over on PS3Fanboy
and over at Capcom's blog
* New move: fake fireball. qcf+short.
* Strong dragon punch is invulnerable on the way up, exactly like Old Ken's, and also always knocks down. It's now a 1-hit move, not 2-hit.
* Fierce dp has bigger arc, always knocks down, juggles against jump-ins, but no additional invulnerability.
* Short helicopter has shorter duration
* Medium helicopter kick goes slightly farther
* Roundhouse helicopter kick goes farther and faster.
* Roundhouse helicopter kick does less dizzy
* Air roundhouse helicopter goes slightly farther
* "Crazy kicks" have simplified joystick motions. New motions: 1) qcf+short, 2) qcf+forward, 3) qcf+roundhouse.
* Damage lowered on first hit of knee bash hold.
* Range of knee bash hold reduced by a small amount.
* Super can now be used as a reversal.
* Roundhouse flash kick now travels forward rather than straight up.
* Super has easier motion: charge db, d, df, f, uf+ kick. (Old motion still works.)
* Super does slightly less damage.
* Uspide down kick is an overhead
* Upside down kick slowed down slightly
* Upside down kick can be performed at any range, not just close range, by holding towards+roundhouse.
* Upside down kick is more vulnerable, allowing Sagat's low tiger shots and other moves to hit it.
* Jump short has higher priority, can hit sweeps.
* Floating fierce move (jump straight up + fierce) can be steered farther left/right.
* Hundred hands easier to execute
* Strong and fierce versions of hundred hands have lower priority and all versions do a little less damage
* Ochio throw now bounces off the other way, preventing Honda from repeating it in the corner
* Ochio throw now deals the same dizzy points as other throws rather than twice as much.
* Jab torpedo can destroy fireballs.
* Jab torpedo travels shorter distance
* Super travels slower before first hit, but travels faster after first hit.
* Super now knocks down and juggles.
* Horizontal ball has safer recovery.
* Horizontal ball with jab and strong have same sound effect and same spinning speed as fierce version.
* Horizontal ball with jab and strong travel slightly shorter distance so whiffed roll into bite is a little more effective.
* Diagonal ball has faster startup and safer recovery.
* Hop move has new command: hold stick left or right then jab+short OR strong+forward OR fierce+rh. (Old motion of kkk still works).
* Hop back builds much less super meter.
* Forward version of hop has slightly more foot-invulnerability at startup.
* Electricity easier to execute (mash punches)
* Super move has faster startup, faster recovery, and always knocks down if it hits.
* Green hand command changed to qcf+p
* Green hand has slightly faster recovery.
* SPD command easier: hcb,f+p OR hcf,b+p. (Original 360 command still works)
* Super command easier, hcb,hcb,f+p OR hcf,hcf+p.
* Running Grab (and double suplex) command is now hcb+k OR hcf+k.
* Running Grab runs faster.
* Kick lariat can now be done with jab+short as well as original KKK command.
* Punch lariat can now be done with strong+forward or fierce+roundhouse as well as original PPP command.
* Kick lariat has invulnerable feet during Zangief's first rotation, but vulnerable feet after that.
* Kick lariat has a different sound effect on startup than punch lariat.
* Punch lariat's initial hitframe now extends down to the floor so it can hit Dhalsim's low fierce or sometimes Guile's low forward. As before, this hitbox is only active for 6 frames out of the entire lariat.
* Hop move can only be done with towards + fierce. No longer possible with back+fierce, back+strong, or towards+strong.
* Hop travels farther forward, slightly higher, and has slightly better recovery.
* Jumping (forward/away) strong has hitbox that reaches slightly farther forward.
* Low fierce has slightly higher hit box, mainly to hit Vega's off-the-wall attacks.
* Removed df+medium kick move.
* df+roundhouse (the "neckbreaker") no longer crosses up, removing the loop of repeated knockdowns.
* Lighting legs easier to execute (mash kicks)
* Lighting legs do less damage and have a little worse priority in Chun Li's stomach area.
* Aerial spinning bird kick can be done with charge down, up+kick, so that you can do it after a headstomp.
* Aerial spinning bird kick travels more straight now, then falls in an arc at the end
* Ground spinning bird kick has a new parabolic arc. It can also air-juggle and deals a fair amount of dizzy.
* Super does slightly less damage.
* Teleport command requires only 2 punch or 2 kick buttons rather than 3.
* Teleport recovery is not longer, but has more vulnerable frames at the end.
* Yoga flame changed to qcb+p so it doesn't overlap fireball command.
* Upward yoga flame changed to qcb+k to match other yoga flame.
* Upward yoga flame now travels way up the screen with roundhouse version.
* Super changed to hcb,hcb+p to match yoga flame command.
* Super has more forgiving timing window.
* Super is now more vulnerable around Dhalsim's head and throwable from behind.
* Super can now be used as a reversal.
* Noogie hold has shorter range.
* Ducking ranged punches no longer cleanly go under Guile's Sonic Booms
* Turn punch and headbutt award less super meter.
* Small and medium headbutts travel slightly farther and are less safe.
* Throw range decreased.
* First hit of throw does less damage.
* Turn Punch can be performed by holding 2 punches or 2 kicks, rather than all 3
* Super does a little less damage
* Defensive backflip command changed to jab+short for small version; strong+forward OR fierce+roundhouse for double flip version (old commands of kkk and ppp still work)
* Offensive backflip can no longer be charged straight back (must be charged down/back).
* Off-the-wall attack no longer knocks down
* Off-the-wall attack has additional recovery, to prevent combos after hitting with it
* New Wall Dive Fake: After going off the wall (charge down, then up+k), you can press kick again to drop without attacking.
* Super has more range, and always knocks down if it hits.
* Fireball recovery is better than New Sagat but worse than Old Sagat
* Some normal moves are from Old Sagat
* Stand strong can be cancelled into special moves, second hit of stand forward and short cannot
* Tiger knee always knocks down and juggles (but NOT into super)
* Tiger knee damage reduced because of new juggle property
* Devil's reverse (charge down, up+punch) has 1 frame of invulnerability at startup
* Stand jab has better priority, can stop honda's torpedo and blanka's roll
* New move: df+roundhouse is a fake slide.
* Jump straight up + strong now juggles the same as jump toward/away + strong
* Hooligan throw motion changed to qcf+p
* Spinning Backfist motion changed to qcb+p
* Spinning Backfist is invulnerable to fireballs during startup (all versions)
* Spinning Backfist's hitbox on 2nd hit is bigger so that it doesn't fail to get 2nd hit if the 1st hit connects
* Cannon drill has better recovery
* Cannon Spike is usually not safe on block anymore.
* Flying Kick motion changed to qcf+k
* Short version of flying kicks have additional frames of partial invulnerability, allowing them to go through fireballs at the start
* Flying kicks have lower priority on first hit, allowing them to be countered air-to-air a little more easily.
* Flying kicks have 5 additional frames of recovery
* Medium and roundhouse flame kicks always knock down and can juggle
* Short flame kick is no longer safe on block from point-blank range.
* Rekka Punches travel a little farther
* Rekka punch motion is a little more forgiving, so it's not as hard to get all 3 in the series.
* Super travels farther
* Fei Long's head is vulnerable during 4th and 5th hits of the super (and can't go through fireballs during that, but still can during first 3 hits).
* The super causes a different angle of knockdown so that comboing after it is difficult/impossible.
* Super meter gains slightly reduced on flame kick and flying kicks.
* Machine Gun Punch, much easier to get all the hits
* Machine Gun Punch destroys fireballs
* Machine Gun Punch does less dizzy and less damage than before.
* Medium and Roundhouse Dread Kicks, 2nd hit sped up so that it almost always hits if the first hit connects.
* Medium and Roundhouse Dread Kicks have a few frames of foot-invulnerability at startup
* Medium and Roundhouse Dread Kicks have reduced damage because of improved ability to combo
* Hawk dive command changed to jab+short OR strong+forward OR fierce+roundhouse while in air (old command ppp still works)
* Hawk dive's bounce changed so it ends with T.Hawk close to enemy and safe on block or hit.
* Hawk dive does not knock down
* Special throw command easier: hcb,f+p OR hcf,b+p, and you can actually start in down/back or down/forward (Original 360 command also still works.)
* Special throw now has a whiff animation if you miss.
* Super command easier: hcb,hcb,f+p OR hcf,hcf+p.
* Several of T.Hawk's normal moves are from Old T.Hawk, such as stand roundhouse and low roundhouse.
* Fierce dragon punch now always knocks down and juggles
* Fixed a bug where a stray hitbox on low strong could be hit from very far away.
* Super meter added and new super move: Raging Demon. Command is jab, jab, towards, short, fierce.
* Super travels slower and farther than the secret version of Akuma
* Super has additional start up frames.
* Super is not able to grab an opponent out of jump start-up.
* Air fireball has new downward angle and causes Akuma to hang in the air slightly when thrown.
* Air fireball can now be done lower to the ground, allowing instant air fireball using "tiger knee" motion.
* Akuma takes more damage than other characters.
* Akuma can now be dizzied.
* Teleport command requires only 2 punch or 2 kick rather than 3.
* Blue fireballs have more startup and recovery. Now same startup as Ryu's fireball and only slightly shorter recovery than Ryu's.
* Fierce blue fireball only has the huge knockback effect from very close range.
* Red fireballs have more startup.
* Helicopter kick has much less invulnerability.
* Akuma's leg is no longer invulnerable during his ducking kicks.