I'd seen alot of visits from the Yahoo spider visiting one of the sites I maintain. Though I just started watching the logs via a new application I wasn't sure if it was normal.
This past week I updated meta data for some dymanic PHP pages and almost immediately noticed an improvement in rankings (in line with our Google rankings), though I've seen these great rankings drop since 4/6.
Hopefully things will improve as the dust settles and we learn what the most important factors are for this current update.