I'm going to disagree and say Google hasn't had many neat ideas in years. I can't think of anything they've done recently that's had anywhere near as much impact as PageRank, AdSense/AdWords, Google Maps, or Gmail. All of those were released in 2005 or earlier.
Knol is a tweaked Wikipedia. Lively is a Second Life clone. Open Social was the response to Facebook Apps.
Chrome, Android, and maybe App Engine are the only recent things I can think of that have any potential.
Maybe (hopefully?) Knol is next.