Question : IM integration with Sharepoint 2010

I read in numerous places that Sharepoint 2010 has integration with 3rd party IM clients.  Office 2010 has it's own client for instant messenger called "Communications Manager" - but it doesn't do what I want.  We already have an in-house IM system - but I can't figure out how (or where to even look on the web) to integrate another IM system with sharepoint and still get presence.  

Perhaps my Google-fu is lacking.  

Does somebody out there know how to do this?  Is Sharepoint XMPP compliant or somesuch?

Thanks!

Answer : IM integration with Sharepoint 2010

Per a discussion with a Microsoft Tech Rep - neither have they.  In fact, they don't even support the idea at this point in time.  My conclusion is that this can't be done - or, at least, nobody seems to have done it.
Thanks!