Just what you've probably read. There's a previous version (gp32x) that had a pretty good following. This is the followup unit which is a little more powerful. It's still "young" so the emulator support is still growing. Stands to be pretty good if the user community continues to grow (not that its bad now). Supports a good chunk of mame, nes, GBA games today and continues to get better. Joystick sucks (though there's a mod to it). Check out the forums for all the details.
I've been contemplating one myself, if for no other reason than it plays movies and can use regular AA batteries (which I can just buy a bunch of rechargables).