I played around with google talk yesterday (I forecasted this in May) both on a windows machine and linux. It works but seemingly is not significantly different from the competition.
That's where the critics are wrong. By standardizing on Jabber lots of application development opportunites are opened up.
An open version of Microsoft's Passport authentication system? This can be done using the jabber interface.
Pushing data to users? Again this can be done via Jabber.
SMS gateway? Try using the google jabber interface.
Hacking together a GMAIL(POP3) to Jabber to SMS gateway in python would be only a few hours of work.
