I already have the Gp2x, and UAE4All running there, even if its a bit slow it still almost matches a A500. On the Pandora it should be more than fast enaugh.
This is truly a cool piece of hardware, the Pandora seem to have almost everything I missed on the Gp2x, wlan, better resolution, faster cpu, keyboard, usb storage support, and it can run ubuntu. Its like a small laptop.
Btw they are closing the preorder for the first production batch this sunday.