How about Magic Lantern developing for us really poor folks with DiG!G II cameras?
Um, ml does run on your 5dc with digic2 just fine, so what's the problem? 30d isn't supported though.
Btw: every digic version needs massive reverse engineering, and only very few people (I can think of 2-3 just now) are able to do that. "Just" coding some modules or patches for ML like I do is different as you're building upon the proven and working ml framework and don't need to do the reverse engineering yourself. But you can ask Canon be more supportive and release the digic specs/addresses and firmware hooks :-)