I am seeing reports at WebmasterWorld of a possible Microsoft update to Live Search.

Senior member, bwnbwn, said it looks like Microsoft is jumping back and forth between two indexes. He said:

Others are not happy with the update, complaining that there is too much search spam at the top.

The last possibly update was in early October. Some suspect this update might have something to do with the new MSNBot Microsoft just started testing.

Forum discussion at WebmasterWorld.