In case you haven't seen this latest post on the MSDN & TechNet Search Blog, I thought I'd point out the latest improvements with MSDN & TechNet site search (also rolled out on Expression).  Our engineering team has been working hard on improving our existing search features--namely our autocomplete feature.  Autocomplete enable you to view terms that relate to the keyword query you have entered into the search box as you type.  Previously, autocomplete was limited to around 30k terms, so the terms that appeared in the search box drop-down were relatively limited.  We've now expanded that list to over 2.4 million terms. From the Search Blog:

"...this means you're at least twice as likely to get a completion when you're typing a search term, and the number of completions you see will be much longer...Note that we haven't improved the autocomplete in the masthead of msdn.microsoft.com and technet.microsoft.com pages yet--for now the 2.4M-term enhanced autocomplete is only on search results pages."

Stay tuned for more updates to MSDN and TechNet site search.  Check out the rest of the post for more info:

http://blogs.msdn.com/msdnsearchblog/archive/2008/05/28/released-improved-search-autocomplete-and-more.aspx