So how will old games work with this crazy controller?
The NES titles will be easy enough: turn the pointer sideways. Those games only use the D-pad plus two action buttons. But that won't help when you're trying to play Super Metroid from the Super Nintendo. We're not really sure how SNES, let alone how even more involved N64 games, will work. The Revolution will play GameCube games right out of the box, and it has ports for GameCube controllers. Right now the answer may be a controller cradle that holds the wand in place and adds a familiar set of buttons. If it works, then playing any title from any generation of games won't be a problem at all.
Above: How to combine 20 years of controlling onto one magic wand?
As for games designed for the PS3 and Xbox 360 and ported to the Revolution, a controller shell could easily make multiplatform games playable on the Revolution. You can slide the controller in, and enjoy Madden or whatever major release you want to, possibly with extra motion-sensitive abilities. Even with more traditional add-ons, the Revolution controller is always receiving all of its crazy data, so you're likely to see some kind of in-between method of control.
Thanks to Nintendo's secretive nature, there are no official photos of most possible controller attachments, unfortunately. Another option could be even more add-ons for the Revolution controller. Itching to play some random SNES games? Grab a vintage SNES controller attachment for the ultimate recreation of the 16-bit days. Accessory companies are likely to try their own ideas for alternate controller choices as well.