This is a bit look-ahead, because it is not released to the public right now but the Features look promising. Search Pages, Posts and Comments as well as a better snippets support (well any snippet is better then none). For getting it to run you need to configure and install Sphinx on your system and then create a search Index. Sphinx provides a pure PHP clientd client-API so there is no need for a binary on that side.
As a small demonstration take a look at the “Search MyISAM in the Post Title”-Demo. Promising, isn’t it?
About one Year later: Sphinx is now used on the WordPress Plugin Directory. Let’s head over there to check if the WordPress Sphinx Plugin is listed there.