If Apple enters the market it would not come at it from the same direction. They like to change the rules of the game so, the new rules favour them. Look at how they entered music players, not with CD players but with MP3. They didn't make a traditional phone either, nor did what anyone expected with a tablet PC.
Same would go for gaming so it's kind of hard to say how they'd compete, if they were even competing directly, or merely having games as an option on a fully feature media centre.
Apple could easily buy over a 3rd party from Ea to Sega, as it suited them. No problem there. But you are highly overrating IPs.
MS made it with a single killer IP - Halo.
Wii became successful off the back of one - Wii Sports. Yeah, yeah, someone will say Zelda but the Nintendo core only number, generously, at 10m. Name a non-casual Wii title that sold more than 10m. Aside from NSMB and Mario Kart which appeal broadly, no Nintendo 'core' IP sells more than 8 generally, although SSBB will be breaking 10m. Wii's success was from Wii Sports by and large.
So Apple would also only need one defining IP. 3rd Parties would provide all the rest from GTA, to Assassin's Creed to FFIV, etc., etc.
Also Sony's various huge IPs have not pulled it out of 3rd place. So IPs are simply not the end all and be all.
As for there being not even money in the market, that's horse-feathers. Nintendo's made billions. Apple would not follow MS & Sony's loss leading model, they'd sell at a profit, and if history is any indication, they'll have a high price and still sell millions. - People will get a third job to get an iGame -
