Apple already tried to take on the Playstation, N64 and Sega Saturn in the 5th Generation and failed abysmally.
http://en.wikipedia.org/wiki/Apple_Pippin
I'm not sure if they'll want to have another go quite so soon, not while the 360, PS3 and Wii are still strong.
Their only chance is to secretly make some sort of unimaginable, all powerful mega-console with plenty of software and AAA titles on release, and kick start the 8th generation early with it's release, but I doubt they have the technical prowess or stable of game developers to do that.
Barring a miracle, playing catchup and releasing second rate versions of existing games for their phones is about all they can do in the game's market, IMO.