Google Releases Page Speed Report In Webmaster Tools
The new feature is the “Site performance” report under the “Labs” section of the tool. The site performance basically shows you how fast your site loads compared to other sites. It also shows you, over time, if your site is getting faster or slower, with a nice graph. Google also lists out specific pages and their load time and then provides tips on how to improve those pages on a per page basis.
Here is a screen shot of one of the site performance reports that I am a webmaster over: