Google has announced that one of the data centers is already running the new Caffeine algorithm. This in not new news, but Google stated that 50% of searches are now coming out of the new Caffeine algorithm.
We know that all of Google will move to the Caffeine algorithm after the holidays, but with 50% of the searches running on Caffeine now is hot news.
I suspect that the week between Christmas and New Years Google will roll out the full Caffeine update. Partly because there are typically low search numbers in that week and that may give Google a chance to tweak some things and kind of do a test run live before traffic returns after the New Year.
On the other hand everyone at Google may be off between Christmas and New Years and so the update will roll out the first week of January. Your guess is as good as mine which approach Google will take.
I am taking a poll, just leave your comments on when you think the rollout will be.