Remember when Microsoft stopped providing updates to the Xbox 360 that allowed it to play old Xbox games, then "coincidentally" launched its downloadable Xbox Classics? It's an obvious trick, but it's one that works, and if this rumor is to be believed, Nintendo hopes to emulate the scam with its own "classics" scheme.
As we all know, the DSi cannot play Gameboy or Gameboy Advance games, due to the fact that the cartridge slot was removed. This gives Nintendo the opportunity to look "generous" by offering old handheld games as downloadable titles on the DSiWare Store. It's ingenous, isn't it? Nintendo fans will lap it up, claiming that Nintendo truly cares about the "core gamer" and Reggie Fils-Aime will be carried through the streets as a king.
The current gossip suggests that downloadable GB and GBA games could be available on an expanded DSiWare store as early as next week, with a possible announcement at E3 paving the way. Until we get that announcement, this is of course mere speculation, but it's one I find highly likely. Removing a system's functionality and then offering the incompatible games as download worked out quite nicely for Microsoft, and there's no reason for Nintendo not to follow suit.
Don't act like you won't fall for it, either. I know I'd download Sonic Advance for my DSi, despite having the physical cartridge on my desk. Hell, it'll be a better use of my complimentary DSiWare points than the crap currently polluting the DSiWare store.