I just checked TTmans site and the good news is he's posted that theres a new build coming soon for his mame4all! :)
Heres what he posted on his blog:
Hello to all of you,
well after some effort between me and Franxis of gp2x original version, I would tell you of merged psp source code to official port, with both preliminary analog support, sound improvements and fixes. A new version will be released as Franxis will complete its own modifications.