It looks that Google might be conducting some sort of major update. Yes, I know - Google is constantly updating, constantly adding content and "improving" the algorithm. But some changes make a bigger impression in the forums then others.
First post came in via WebmasterWorld at around 4:30am (EST), saying "There seems to be a roll back now... seeing the same old results for a few highly competitive 2 word keywords." Several members support his findings, even senior member, nuevojefe, added:
Very interesting changes I'm seeing. Major swings in a high traffic niche, but not much different in other niches I watch.
Seems new sites of a certain criteria are being allowed to jet up more though. Surprised to see new sites able to be propped up by network linking.
The DigitalPoint Forums thread has members who are commenting about a loss in traffic. Some members have posted charts showing a major drop in traffic, possibly due to a Google update.
So I think we have sort of major Google update going on.