"Currently AJAX results are just a test on Google. At this time only a small percentage of users will see this experiment. It is not our intention to disrupt referrer tracking, and we are continuing to iterate on this project and are actively working towards a solution. As we continue experiments, we hope that this test may ultimately provide an easier solution for our customers and a faster experience for our users. For more information on the experiments that we run on Google search, please see http://googleblog.blogspot.com/2006/04/this-is-test-this-is-only-test.html"
the press release on Google Chrome OS is very telling on Google's desire to improve search speed:
"We hear a lot from our users and their message is clear — computers need to get better. People want to get to their email instantly, without wasting time waiting for their computers to boot and browsers to start up. They want their computers to always run as fast as when they first bought them. They want their data to be accessible to them wherever they are and not have to worry about losing their computer or forgetting to back up files. Even more importantly, they don't want to spend hours configuring their computers to work with every new piece of hardware, or have to worry about constant software updates. And any time our users have a better computing experience, Google benefits as well by having happier users who are more likely to spend time on the Internet."
I think it's not about Microsoft really. Microsoft's OS just happens to be in the way of Google for them to have more people search - having a clunky OS just delays people from searching not by the milliseconds but by the minute (sometimes by the hour! okay half-an-hour!)