Forum Moderators: open
When all of the datacentres have the 'new' index, you'll see it mentioned on WebmasterWorld, I promise. Until then, I highly recommend checking heini's link, as GoogleGuy has been much more talkative this time than in the past.
When those nine return the same backlinks, that would normally be the sign that the update has finished.
It's best to think of www.google.com, www2.google.com, www3.google.com and toolbarqueries.google.com as load balancing domains that can be pointed at datacentres.
Historically, www2.google.com and www3.google.com have been pointed at datacentres with the new index some time before www.google.com starts to show it. There's no reason why any of these four domains shouldn't swap between old and new indices during the update process, hence the term 'Google dance'.
The unusual thing this time is that the link: search and Toolbar PageRank returned by the nine www- domains appear to be old. It would seem sensible to expect a second half to this update, unless Google have something else up their sleeve.