I really don't see how drastic changes are outside of Google's ability. Google (and Yahoo) can both bucket-test drastic interface changes to 1% or 0.01% of thei

I really don't see how drastic changes are outside of Google's ability. Google (and Yahoo) can both bucket-test drastic interface changes to 1% or 0.01% of their audience, effectively simulating a small startup doing the same thing. (Related: post-search deal with Bing, experimenting with user interface in this way is Yahoo's explicit strategy for competing in search.)