I was going to make an Invisible Kart LOLcat joke but I just can't be arsed to do so.

So, about 12 hours in (no, I did not spend all of that time playing) and this is what I have.

Friend Code is - 1160-9838-6084 (Craig)

Controlls -
(Note: I haven't been able to get my WaveBird working with the game. I'm probably missing something obvious with it so I'll figure it out)

Controls have been streamlined from previous MK games; the break has become the drift and depending on your drift shift (more on that later) you will hop when you press break).

Early reports of the non wheel controls being gimped are a load of nonsense, the apparent missing manoeuvres (the tricks and wheelie on the bikes) are mapped to the d-pad in the classic controller.
Speaking of Tricks, the tricks are easy to use and will give a speed boost on landing but they can easily mess up a jump if you get overzealous with them. Also, the wheelie gives you a small speed boost at the cost of manoeuvrability.

Between Wheel vs Classic Controller (haven't tried Nunchuk or GC Controller), I think most MK veterans will feel more at home with the CC for the moment.
The Wheel set up seems to be perfectly fine but I've found myself using items when I meant to jump by association of the original setup and that I felt the lack of a neural snap back to sorta leave me floating.
With enough practice, this will probably not be the case but for now. I'm happy to use the CC.

Courses
From the off, You are given 16 out of the full 32 tracks with each of these being split into four cups; two new and two Retro. So far, I've tried about two thirds of them and there's no real issues with the course. I really like the last course of the Mushroom Cup: Toad's Factory because it more or less one giant conveyors belt of nonsense.

items
No real change to this but I feel that the items from MKDS have now made the race a tighter deal than previous MKs. I haven't seen many races where the last place person was half the course away from the rest of the group.

music
Music is standard MK fair (in that it's good) and all of the Retro Courses have been arranged. Simply put, Snes Battle Course theme was awesome.

online
And now, the bug bear, if I think this is good, I'm a Nintendo apologist and if I think it's bad, I'm one of those screaming twats who think spending their life screaming profanities to people in Halo is a good way to live.

Anyway, online works more or less like it's DS counterpart; you can join a group match (which isn't faceless par-ce, you get to see everyone's Miis) that's ether Continental or Worldwide (Though there was one Continental match in which an American was in there, nothing wrong with that but it boggled me) and doesn't seem to be all that bad.
There's the friend's option but I haven't got many of those so it will probably take a while to get that working.

In addition to this, MKW has the option of downloading ghosts and, even better, watching the replays of any ghost you download so you can see the method to the madness. Good stuff all in all.

Yeah, that's more or less it. Koopa Trooper in the NokoBike for the win.