There is a single post at WebmasterWorld with one SEO suggesting there was a Bing Search update recently.
The WebmasterWorld member, who is a long time member, said:
Very rarely do I notice updates in Bing but this one seems to be rather huge, major shakeups across the board. From what I see it is pushing "Brands" as well, though it hasn't been pushed to Yahoo yet, can you give us an update BingDude?
I did check the stats on this site and it seemed like we had double the traffic from Bing yesterday than we typically do on a weekday. But looking at a single day compared to other days is never a good indicator. I do not run ranking reports, so hard to confirm this myself.
We do not have confirmation from Bing yet, but I will try to get it soon.
To push out updates now, right during or prior to the shopping season is something most search companies avoid. At least since the Google Florida update in 2003.
Forum discussion at WebmasterWorld.