There's a good article over on ars technica about the direction that Google is taking the Google Talk offering. Specifically they are adopting the Extensible Messaging and Presence Protocol (EMPP) aka Jabber. This will make interoperability with other EMPP / Jabber servers possible and eventually open the door to interaction with other instant messaging services.

IM and its associated protocols represent a threat risk for network administrators and many simply block the traffic. For other companies the use of IM and the associated presence capability (I'm away or availble) is an essential tool. What ever position your company takes it makes sense to keep up with where things are going in case you find yourself in need of supporting or recommending a particular product.