I’ve ripped out the guts and redone the search on the WordPress.org support forums in the hopes of making it something more people will use. Try it out! The new system searches the wiki (hosted on a different machine), thread titles, recent posts, and does a FULLTEXT post search for the most relevant posts. It has contextual search highlighting (like Google).
When I have some time to get back to this every section will have a “more of this” link to take you to more results (paged). It does this currently with the wiki search, counting the total results and linking to the wiki search directly if there are more than 5 results. Probably still a few bugs to work out. The fulltext query was taking over two seconds to run until I tweaked the JOIN type to get the MySQL optimizer to use the proper index and join order. Everything should validate as XHTML.
A new system is also in place to inject custom results at the top of the page. We’ve been logging searches for the last few months (over a 129,000 so far, about 43,000 unique searches) and I’m going to be working closely with the documentation team to identify which searches are most common and what tailored information would be best to present the user with when they search for targetted terms, be it a blog post, an external resource, someplace on WordPress.org itself, a wiki page, or a specific thread. We can watch trends and spikes in searches to identify any problems in the application itself or features that may be insufficently documented or hard to use.
The work is far from finished, but I think it’s a strong first step into fully integrating search as a support mechanism and bringing the WordPress team even closer to the pulse of the users.