Seems like a good project to start on (list first) then. I will do so over the next week or so, digging up what I can.
Clarification: Do the 32-bit apps rely on 32-bit dependencies (in the case where SomeApp requires UsefulApp >=1.4 to be installed, and UsefulApp has both a 32 bit and 64 bit version both named UsefulApp) or can they use the 64-bit dependencies, or is it case-contextual?
That is a good question,but the best answer that I can give is: It depends.
if SomeApp requires UsefullApp for its functionality then the 64bit version would be fine, but if it needs it for its libs then most likely it will need the 32bit version.