Anyone with any amount of technical clue who has used Vista has invariably figured out that the 'Windows Search" (wsearch) service is responsible for a lot of the CPU and disk suckage that seems to start at random times from out of nowhere and last for hours. :) I personally have a fairly robust set of systems I use every day and I have learned to accept it because for me the benefit outweighs the cost.
However there are those for which this is not true and during the beta it was not un-common for me to see advice given on various DLs internally like "net stop wsearch" in response to "why is Vista so slow?". It was usually the first on the list of things to try when talking about how to make Vista run faster. (And I would then invariably see replies of "but search runs at low priority and it shouldn't be causing that much performance impact" etc. however theory and reality didn't always line up . . . especially on older hardware. :)
Anyhoo - with that I give you this: http://windowsvistablog.com/blogs/windowsexperience/archive/2008/06/03/windows-search-4-0-released-to-web.aspx
Hip hip hooray!