page speed would be one of the factors built in to their ranking algorithm (The code that Google uses to decide how high your website or blog appears in their search results).
Somewhat ironically, one of the things that has been slowing things down (at times) has been Google's own analytics code, which is used by a huge base of large and small websites.
In reality, the amount of websites that 'load the code' each day (each minute?) is enormous and some credit goes to Google for most keeping the program alive and well ... and pretty fast .... most of the time, but there have been complaints.
Google Analytics is getting faster.
Announced today, the embedded code is changing to a new 'asynchronous tracking code' (that came out of beta just last week). It's available now ..... and Google is urging website owners to switch as soon as possible.
More information and instructions on changing your site (and making rendering a little quicker!) can be found here.