The user numbers coming out on Google Talk are staggeringly terrible. Comscore usage numbers show that nearly a year after launch Google is a distant, distant 4th after MSN, Yahoo and AIM. They hold a pitiful 1% of total instant messaging market share, with 3.4 million unique users in May 2006. See the Comscore chart below for more details (I wonder where Skype IM falls in those stats). Note that Comscore does not include Google Talk usage within Gmail itself (where it is embedded), but even factoring that in, the numbers are just awful.
Where does Google go from here? I suggest they roll some heads and figure out a real product strategy.