It's a different sort of market. I think the best sort of games that are on iOS are the kinds that require little immediate time commitment. I think games that will eventually come to be hugely successful are games that essentially are continuously going, having players continuously build a city or an empire of some sort.
Although there are some very nice looking iOS games coming out that seem to be more like Wii games. There is that Rage game that is beyond the level of Resident Evil UC. It's also an excellent platform, even though the phone itself only has a very small percentage of the mobile market, it has its compliments in the iPod and Tablet markets - and unlike other mobile platforms, developers do not need to port on even close to the same level as all other mobile platforms; there are only three screens to worry about old-iPhone, iPhone 4 (which I assume will be the general screen res for the next 2-3 iterations at least), and iPad.
Although, despite this, I don't think it will ever be in direct competition with the mainstream videogame systems, at least not in the foreseeable future. Going in the interface direction required for a DS or PSP would be a huge mistake for a mobile phone (remember N-gage? That was also by the mobile phones giant Nokia which has sold billions of phones - last year alone it was 472 million phones and $70 billion for Nokia), and that is the only way it will directly compete.... Although there is no reason why it should, as the mobile market phone is WAY larger than the videogame market.
I describe myself as a little dose of toxic masculinity.
