With the release of 3.0 for the I-Phone and I-pod touch Apple has started to mention third party game accessories. Now I'm not exactly sure what these could be, but man would it be sweet if we could get some kind of controller add-on to the system. I think that would definitely help out first person shooters, well actually with almost every title it could probably help out a bit. Though I don't know, it might start feeling Wii-mote like.
Also there's no guarantee of who is going to have this accessory, which I'm imagining in my head, which would have creating games for it a huge risk. Which brings up an interesting point. Why would you change the way that you create games to center around a third-party accessory, wouldn't it be better to just focus on the native features, and not worry about how many people will be able to play this because they may or may not have the add-on.
I guess we'll see when I'm sure some of the third party controller makers for the consoles start throwing their weight around on the accessory market for Apple's systems.