People say mobile gaming will challenge consoles because in terms of risk to profits they are much more attractive to develop for. AAA titles are extremely expensive to make and many of them flop. Compare that to a simple game (like Angry Birds) that costs almost nothing to make, immediately turns a profit and runs on hardware everyone (even non gamers) own. If it flops the developer is out what? Ten grand? Compared to a 100 million dollar game (like GTA4) the risk is insignificant.
That is the argument. I don't know if I agree but it has some very valid points. As a business model cheap cell phone games are much more attractive to make.