gouri - 7:39 pm on Apr 6, 2010 (gmt 0)

I am seeing today for a couple of competitive phrases, a number of sites that come up when searching for those phrases moving back around 150 positions.

I think it could be because of Google adding datasets to their index as they prepare to rollout Caffeine.

Does this sound like a possible explanation? When might the sites that have moved back go back to around where they were ranking?