The FAQ, incidentally, can be found
here if you are not sufficiently good at navigating message boards to find its location in the
General GP2X / XGP Talk forum. And speaking of that forum, that is really where this question should have been posted. This forum is for people talking about HOW to develop software for the GP2X, not whether or not certain software WILL be developed.
And to reiterate, lest you strain your brain too hard trying to find it in the FAQ, (the site that it links to seems to be down...) no, the PS2's capabilities are well beyond what the GP2X will emulate. The GP2X's emulation will mostly be of older, classic systems like the SNES, Genesis, etc. No doubt someone will also attempt some kind of PS1 or maybe even Saturn emulator, but those will be a
very long time coming, I assure you.
As for what makes the GP2X so great - well, that depends on what you want from it. It's a powerful handheld, by comparison to its predecessor, the GP32, or even most of its contemporaries like the DS or the PSP. (Power is, of course, a relative thing. The PSP has a 3D rendering chip, while the GP2X has none, but the GP2X has much more memory. Just to give one example.) It uses standard SD cards to store its games instead of proprietary cartridges or discs, which means games can be distributed online and downloaded and that you can put files like MP3s and DivX movies from your computer onto the card and (thanks to the built-in media player) play them. Also, the console is completely open, which means that anyone can get the information and files needed to develop games for it. (If you aren't aware, it usually costs game companies thousands and even tens of thousands of dollars to buy a "devkit" from a console manufacturer to make games for their console.) So any hobbyist who owns a GP2X can make games or programs for it, which should result in lots of fun and unique home-made games from fans ("homebrew games") as well as, no doubt, several emulators being written to allow the system to play games from other, less powerful consoles of yesteryear, like the NES, Amiga, SNES, Genesis, etc. And if you don't like small portable screens, like my mother-in-law, the video can be output to a TV so that the games can be played as if one was using a regular console.
All-in-all, the GP2X is a very impressive piece of work, and people are excited about it mostly because, like with a PC, anyone with the right technical know-how can make games for it, which sets it apart from almost all other gaming systems. (Well, except for its predecessor, the GP32, of course. And some unfortunate flops like the Zodiac and its kin.) And that means there will be not only professional, commercial games for the system, but games made by people who can focus on making their games fun instead of focusing on how much money their game can make. In short, games that AREN'T carbon-copies of other games.
I could rant on forever about the joys of homebrew, but I guess I'll cut myself off here. Hopefully now you have a greater understanding of what makes the GP2X different from its contemporaries like the DS, the GBA, and the PSP.
In the end, we don't know for certain just WHAT the GP2X will be capable of, because it isn't out yet. It should be out soon, and I can't wait for that day, but until then we can only guess at what kinds of games it can do and how much 3D it can handle and what other consoles we'll be able to emulate effectively. My money says anything from the 16-bit generation back should be feasible with talented coders working on it, though of course such efforts will take time to produce really good work. After that - well, I'm just not sure. Remember the rule that to emulate a system, you need a system that's ten times as powerful, and I'm not sure the GP2X is enough when it comes to late-generation consoles. But I guess we won't know until we try, huh?
I should also add that games made FOR the GP2X will be able to push much more impressive technical feats than emulated games, simply because they'll be able to use all the GP2X's power for themselves instead of having a layer of emulating eating up resources and things. Homebrew games will be able to be as advanced as current handheld games on other systems, I should say. But that will be for games made specifically FOR the GP2X, not the emulation you seem most interested in. Ultimately, the limitations of what will be possible will be determined by the programmers who slowly learn to wring more and more out of the system the longer it is around.
(
EDIT: Added a long rant to the end because the FAQ has several links that seem to be down today, so I wasn't sure it could answer the question fully.)
