From Game Stooge:
Matt Casamassina from IGN posted a while back that he had played Halo on the Nintendo DS. It didn't take too long before this was debunked as strictly a rumor and was burned into vaporware. However, in IGN's Wii-k in Review podcast for 6/15/2007 (ie: last nights) Mr. Casamassina brought it up again, and had this to say:
"It's a real game… we're going to lay down some ownage next week or soon afterward by showing you guys that it is a real game."