Well, Squige, since you asked...
I'm all the way "new" to the GP product line. My new GP2X-Wiz is one day old. FWIW, I spent several hours trolling boards and sites learning about the hardware differences. Learning is an ongoing and changing process and you have met me at the GP2X beginning. As you pointed out, apps compiled for the GP2X should not be expected to run on the GP2X-Wiz. The units sport different cpu's. Recompiling GP2X apps will be required. In other words, for those still trying to figure out what their new GP2X-Wiz can do, there is no backward compatibility with applications (emulators) compiled for the GP32 and GP2X. If there is a GP2X app you were hoping to run on your GP2X-Wiz, you will have to get the source code and recompile it yourself, or wait for another developer to do so.
As you likely know, there are many sites asserting that the GP2X-Wiz is a "... mini GP2X." For both good and bad reasons, these statements are not entirely true. For anyone still following this thread along, my new GP2X-Wiz is nicely running emu for NES, SEGA, and MAME4ALL (~1800 titles). It's a great unit.
As for my Lynx emulation plea, well... the platform holds a special place in my heart. There may be only ~70 titles, but they all ran on the first portable, color, handheld gaming system.
Squidge, I think you came down on me a little hard. Dinging my "reputation -1" is a harsh welcome to the GP2X(Wiz) world.
Just my 2-cents