You guys should hire me for SEO consulting if you can't answer this one in-house. ;)
Jokes aside: BingHoo share, followed by comparison to Google (which makes it harder to see).
http://images1.bingocardcreator.com/blog-images/hn/nostra-an...
http://images1.bingocardcreator.com/blog-images/hn/nostra-an...
I'm not specifically aware of anything material which would have materially affected BCC's performance on BingHoo in the last 3 months, and the big candidate for affecting performance at Google (Panda or whatever you guys call content farming internally) largely seems to have missed me. When you compare year-to-year to back out the seasonality, though, both Yahoo and Bing show strong growth in my Jan/Feb/March numbers and Google growth is much more muted. Feel free to backchannel me if you want the spreadsheet.
For reasons known only to the Excel gods, the X axis considers the last data point (March) to be in February.