So if I'm on the go, and I want to play a sort of game that benefits from buttons...?

Just gonna toss my 2 cents into the ring about the obstacles to innovation in iphone games in particular, in my humble the most problematic part is the screen size, mostly because in order to touch the screen I will be blocking a part of what is already a fairly small screen, which can impact even a fairly simple and straightforward game such as jetpack joyride. If you attempt to do even more elaborate things with the touchscreen you would at least temporarily be blocking even more portions of the screen. I think this is a big part of why games like Zombie Gunship, Zombie Highway, Temple Run or dare I say it, Angry Birds are successful; because the temporary blockage of viewing area (or lack of need to use the touchpad at all) does not negatively impact the game play. So unless people invent translucent thumbs or phones with really fucking huge screens (not ideal for phones) I think it will be tough to really on the iphone. The ipad on the other hand has a lot more potential due to the much larger viewing area.