Over the last week or so some changes have been made to the Public IM Connectivity connector to expand the number and type of people that you can add to your contact list if your company subscribes to PIC.
Previously, it was only possible to add addresses that end in @yahoo.com, @aol.com and @hotmail.com (and relevent other hotmail addresses). One of the big problems with the previous PIC configuration was that it did not allow for passport addresses that were unsual. When I say unusual I mean firstname.lastname@example.org, the problem with an address like this is that PIC didnt know whether to send it to MSN, Yahoo or AOL. This has been solved now so all you need to do is add the contact as yourname(personalemail.com)@msn.com and it works :-).
This is great news and if you only ever want to talk with work contacts it essentially means you have no need to have MSN Messenger or any IM client on your desktop except Communicator.