All I know is that the Intel-only QMC2 package has been built on a Lion (or Mountain Lion) system... and yes, it comes with all the Qt framework dylib's it has been linked against.
The actual problem seems to be some library incompatibility, though:
Dyld Error Message:
Symbol not found: __dispatch_source_type_vm
Referenced from: /Applications/qmc2/qmc2-sdlmame.app/Contents/MacOS/../Frameworks/QtWebKit.framework/Versions/4/QtWebKit
Expected in: /usr/lib/libSystem.B.dylib
The usual answer to this sort of trouble is to build Qt (and QMC2) yourself
. Since QMC2 Arcade isn't linked against QtWebKit it's the only app that runs (it's 64-bit as well, BTW). However, I doubt that your issue with SDLMAME/SDLMESS/SDLUME is exactly
the same because of this.