Personal, I would like to see Zelda. That would kill any sliver of a doubt left in gamers that Nintendo is still with the... "Core" (ugh) gamers.
But it will be something else... "Wii something"
Predictions for 2009: (Right) (Wrong) (Partial)
Pokemon Gold/Silver DS Japan in September
NES colored Wii and SNES Classic Controler for Christmas
Super Role Bros for Christmas
FF Remakes announced; VII PS3 VIII 360 IX Wii
New Super Mario World November 2009