Windows Desktop Search details?

I'm looking for a good article or post describing Windows Desktop Search.
I'm confused on multiple levels, not the least of which concerns the various
versions of WDS, or similar MS software, released in XP and betas of Vista.
I've lost the thread on where we are with searching and where we are going.
If anyone can summarize that, it would help.

I am trying Vista RC1 on one machine right now. I would be very interested
in an article on the details of the search feature. What does it do, how
does it do it? What are the various options available? When I use it, I
sometimes get the expected results, and sometimes not. I've reviewed lots of
posts in the Vista newsgroup, but only glean snippets about the search
feature. Can someone cite an in-depth article about this feature? It seems
to have powerful potential, so I'd like to learn about it now.

Thanks
Dave