I might point out that Carmack has little (any?) hands-on experience with the PS2 or Xbox, so I'd take his comments with a grain of salt, especially any claims about the relative power of each of these machines versus the iPhone--it's not as if he can simply look at the hardware and instantly calculate its relative horsepower (as some on this thread seem to imply) and is probably basing his comments on what he's been told or read, rather than what he has actually experienced by briging his coding superpowers to bear to squeeze the most possible from the machine in question (in other words, if he isn't building his engines from the ground-up to work on a particular piece of hardware, there is almost always going to be waste and inefficiency when porting that engine around to a host of platforms).
It's also worth pointing out that he's been neck-deep in x86 CPUs for nigh-on two decades, so when he comments on ease of use and horsepower of console x versus console y, you have to at least admit that he might be somewhat biased towards those devices/machines/OSes that he is most familiar (this only stands to reason), so a machine like the PS2 (or PS3) would be relatively alien to his experience since he never really spent any time trying to get much out of them. Meanwhile, over on the 360/iPhone side, he's used to the tools or the hardware or the OS (or all of the above).
This, of course, isn't to say he couldn't. I'm certain that if he sat down and spent a year working solely on the Cell architecture we might all be blown away. But he doesn't and he won't because that's not where the money is as far as id is concerned: the money is on PC, 360 and, apparently, iPhone (and a lot of work for both the PC and 360 is very portable with little waste when transitioning engine work to and fro--the same might very well be the case with the iPhone).
Also, by way of an analogy vis-a-vis Carmack's statements on relative console power levels and their general value in the debate: It's a lot like a fantastic athlete in football that thinks he also knows all there is to know about playing soccer when he hasn't spent very much time actually playing it. Sure, some of the knowledge between games is transferable, but the nitty-gritty, the essentials, might not be quite so easy to grasp without a lot more hands-on time learning the ins and outs, the nuances, of the less-familiar game. This superficial handle on things, however, is enough to convince the average layman that, hell yeah, this guy knows everything there is to know about soccer, even if, at heart, he's really only a great football player and athlete but not neccesarily a great soccer player.
Also there's the question of what his criteria is for making such statements: does he mean it's more powerful because it has more RAM? Is it because the development environment is much easier (believable since it's been years since the Xbox or PS2 were in vogue and the iPhone is, of course, bound to have better--or at least much newer--tools)? Could it be that it's a tactical business decision and that since id is investing substantial resources (read: money) in the platform, it helps if he talks it up to get people to pay attention? It could be all of the above, none of the above, or a mixture (or something else entirely). The point is, do we even know what the context is for his statement(s)? After all, the Sega Saturn had more powerful hardware than the PS One, but getting to it required such a massive amount of work that it wasn't worth the investment to struggle with its idiosyncracies.
Another thing: a lot of you need to really stop with the "he's a god, he knows all, if you question him you will burn!" nonsense because nobody is perfect/right all the time, regardless of how skilled they are at a given craft/trade/profession/etc. Even Einstein made massive, massive fuck-ups in his career and he was one of the most brilliant men to in human history so it might just be possible that the All Seeing Eye, err, Carmack might not always be right just because he's John Carmack.
