Whatever is rolling out it doesn't feel like Panda. We didn't get the typical deep crawl leading up to it. This crawl was similar to the other updates that have been rolling out of the past couple weeks now. Pre Panda crawls for our site are typically 2-3 times the norm.
You would think that when the update to Panda hits they will do a really big crawl of the web. It's been almost 10 weeks now since the last known Panda.