I'd love to hear how the durian team is managing linked character assets in the project.
In particular, do you have a low poly(proxy) mesh along with the hi-poly 'render' mesh in the character blend file? How are you handling this in the scene file when you link to the character group?
I'm assuming that ideally, one has the same armature deforming both the hi-poly and low-poly meshes so you animate once, then view on either; lo for tests, hi for final renders, right? I'm having difficulty getting this to work in 2.49b... Have you made improvements in 2.5 to make this possible?
I could be way off, so it would be great to hear more about your approach in durian:-)