Problem is that a lot of the active coders for the Amiga community seem to be more into "next-gen" systems (i.e. PPC & MOS/OS4.) Even the 68k stuff seems to be directed at 040/060 systems with RTG. Personally, I'd like to do some development for stock A500 (I already have some projects in mind, but I'm tied down with MSXDev and other stuff at the moment,) but I seem to be in the minority...
Still, maybe if one were to set up something more analagous to MSXDev, with the community-donated pot and assorted prizes, it might get a bit more attention...