Messenger via XMPP
This week at BUILD, Microsoft announced that Messenger connect would be renamed to Live Connect and as part of that, they are enabling XMPP access to connect to the Messenger service.
The ProcessOne blog has some details on the technical aspects of this for those interested.
However, it seems that requires a proprietary authentication method so current clients won’t be able to get on (naturally I tried anyway to see what happens but it doesn’t get very far).
It will be interesting to see what happens with this in the coming months when there is more information. Although third party clients have had their own implementations of various versions of the Messenger protocol for a long time, presumably if they were to use XMPP instead they could avoid breaking them and phase out older versions of the protocol.
ADDITION 12/15: They officially talked about this on the Inside Windows Live blog.