There appears to be some early reports of a Live.com or MSN Search update taking place now.
A WebmasterWorld thread has a few signs and signals from the SEO community that such an update is currently underway.
It is currently not clear if it is a global change or if this update is just affecting certain industries.
We have been seeing some wild swings in MSN search lately, anyone seeing an update in rankings?
Of course, some are seeing poor quality signs.
I thought they had resolved the blogspot problem, but today I see several junk pages ranking well, including the #1 spot for the phrase I am monitoring.
Forum discussion at WebmasterWorld.