When you have federation between two OCS R2 companies it’s not just IM you can do.
Normally we talk about IM and presence when talking about federation and that’s cool you can do IM and see presence, and maybe that the most important part, when you start doing federation.
When you start using all the other features internally (Video Voice desktop sharing etc.) and maybe have done some phone system integration it’s naturally start using this together with your federation’s partners.
And it’s possibly to do Audio (Communicator to communicator call) and video (P2P) and even share desktop, and you can do web conference, but this is also possibly with anonymous.
MSN-Yahoo-AOL (PIC) Public IM Connection: it’s only IM and presence for now ……… this could be a nice feature ….. … and who knows :), maybe next version or nextnext version, MSN and OCS would be able to do this.