Here's a few quick items to start this thread:  for LinkedIn integration, I'd like this support:

Add new LinkedIn name to WeMeUs, add new WeMeUs names to LinkedIn;  pick up events of interest in LinkedIn and make them each an entry in activity (or appropriate field if other than activity);  ditto for invites and status (accept/ignore/reject);  graphical notation on MyConnections that denotes which connections are on LI or FB (or other key site); pick up key profile info and update MyConnections contact detail with it.

A question for those of you reading this:  how many of you have friends or contacts on both LinkedIn and Facebook?  How about Plaxo's Pulse or Spock?  Any others you are using?

I have about 140 connections on LinkedIn and about 80 or so on Facebook.. I routinely encounter heavy networkers with 300-400 connections, or, more rarely, HR/recruiters with >500 connections..