It's December, the last year of 2008, and webmasters have started guessing what's up with Google this month once again.
New sites are fluctuating with their rankings; one webmaster reports that his new sites (2 months old or less) are showing up in the top 10 and then 12 hours later, they're not even in the top 1000. It seems that this is a cycle. Some say it's just a sandbox.
Another observation relates to sitelinks. It seems that there are questions regarding sites that have sitelinks in Google's results. Do those mean that those pages are refreshed more often? Crawled more often? Not necessarily; getting sitelinks means you're a more "popular" site (you have more attention), but having sitelinks isn't a factor. The former brought upon the latter, after all.
A third observation relates to a "disconnect" between index pages and inner pages of sites. These pages were never linked together in the SERPs. Tedster expounds upon this idea and says that he observed that the second results from a domain aren't always indented. Sometimes, though, they're indented too much.
Forum discussion continues at WebmasterWorld.