I remember Franxis saying a couple of things on the topic. He didn't seem all that enthused about Pandora. He said that despite all the extra power, it wouldn't necessarily play more recent games because they relied on large amounts of RAM. It would still be a significant improvement of course - you just couldn't expect to play games from the last few years. (You might find related info in Duddyroar's GP2X feature in RetroGamer, the one he scanned & posted).
I also remember Craigix offering a Pandora to Slaanesh, I think he'll be porting Mame4all to Pandora.
[edit] Cached thread:
http://209.85.173.104/search?q=cache:Gd ... en&strip=1
[edit2] Thread which seems to confirm Slaanesh is on board:
http://209.85.173.104/search?q=cache:sq ... en&strip=1