A post today from SEO Black Hat seems to indicate that bounce rates are already a significant factor in ranking. They provide the following screenshots showing Google Analytics data for a "white hat" site (click any of them to view the larger versions at SEO Black Hat:

Overall Traffic

Google Traffic

Bounce Rates

Hmm. See any correlation there? "This is exactly the pattern you would expect from a program designed to flush out terms with higher bounce rates and test them across other sties," writes the post’s author QuadsZilla. "Moreover, this isn’t the first time I’ve recognized this pattern, it happens every 2-3 months on average." Quadzilla then notes the absence of any such information in Google’s SEO starter guide, but points to a few cluews in the Analytics support page.

So, maybe bounce rates are something that you should be worried about. In all honesty, you should’ve been worried about them anyway, if nothing more than to keep people at your site. Nevermind if they got there through Google. The following video from SES a few months back goes over some Bounce rate information as Mike talks to Avinash Kaushik, author of Web Analytics: An Hour a Day, and Google Analytics group manager Brett Crosby.

Jason Miller offers some additonal insight based on the video, and Quadzilla is promising some tips on reducing bounce rates in the future.