I don't quite know what to make of it yet. Been using it for a couple of days without much excitement, but I am pretty sure there is a lot more smarter algorithm behind the left navigation bar. It learns about your search processes the more you use and adapts for better information display.
For example, I would often use: regular and news search (last 24 hours, last week), as well as "define: keyword" search, and now I noticed most of the time it gets me all these results at the top for my searches, which saves me time.
But then again I might be completely wrong about what's taking place in reality.
Regardless, I don't mind the new look. It hasn't changed a lot and I am sure we will all get used to it with time. Design-wise, I've always thought Google was one of the worst companies when it comes to packaging products and services.