Don't think it supports multiple saved connections well. What I do is have many copies of remote desktop connection and use quicksilver to get it to remember which saved connection profile should open up in which rdc. e.g. quicksilver - type name of rdc connection file - press space for open with - then choose one of the rdc executables. If you use always open with a few time quicksilver will eventually put the right one at the top of the list. So I have a connection pref file and a rdc with similar names.

ah, it seems to crash on osx, im am not the admin so it could be a rights issue

excellent, I was looking for this!!!

OMG! Thank you so much! I'm a Mac web-developer in a PC-centric office. Everyone here teases me because I'm limited to only one RDC connection at a time. Ha! Not anymore!