If it was a portable gamecube with backward capabitlity, that would be one of the smartest moves Nintendo have ever made. Think about it, Nintendo already has many companies wiht dev kits, making games as we speak. Even more companies would jump the ship if a handheld that played GC games came out. Every third party company would want to develope for Nintendo, becuase not only will they have there software available on the gc but on the pgc. People love handheld gaming, but its not entirely mainstream and as popular as it could be becuase of graphics and such. Nintendo would do away with that barrier.
Now combine that with great advertisement (every needs to some how find out there is a product like this...everyone) and some way to play multiplayer games(wireless would rule) and there you go the hotest game system around. They could charge $150 for it and people wouldn't mind........hell I wouldn't.
I'm getting ahead of myself. I remember that Cap, and I also remember some press conference when the gamecube was finally fully unvieled, some news reporter asked if the disks due to there small size are going to be used in any future Nintendo handhelds. Nintendo said maybe then quickly changed the subject. (paraphrased obviously)
EDIT: forgot there was another page of comments to read before i posted, and makes this completely illrevelant.