How many modular PSU's are there out there? I can only recall seeing one example, and that appears to be an Antec:
http://www.frozencpu.com/cgi-bin/frozencpu/psu-31.html
Anyway, there's always more molexes than required on a high spec PSU, so why not modularise the connectors? I suppose the only problem then is controlling how connectors are added to preving overloading the cables...
Thoughts?