Google Panda will soon evolve from monthly (or so) manual refreshes to a constant part of Google's real-time algorithm, according to Google's Distinguished Engineer Matt Cutts. The latest (possibly final?) Panda refresh is expected today or Monday.
Now if Panda hits your website for having "low-quality" (thin) content, it may be harder to detect in analytics due to this new integration with the main search algorithm, but it could mean a faster recovery.
"Rather than having some huge change that happens on a given day, you’re more likely in the future to see Panda deployed gradually as we’re rebuilding the index, so you’re less likely to see these large scale sorts of changes," Cutts said at SMX West.
Meanwhile, online chatter seems to indicate that the latest, and perhaps the final, Google refresh may have started hitting websites yesterday afternoon, but there’s no official word from Google so the traffic flux some websites are experiencing might be unrelated to Panda.