I threw this together this morning, it’s called WP Sauce:
The best way to use the site is to dig down in the results with the tag cloud in the top right of the screen. So, if it is WordPress themes you are after, just click themes in the tag cloud. Likewise with plugins, or maybe tutorial.
Hopefully this will be a useful resource, not least because it will keep itself updated more or less automatically. After all, no-one’s going to stop bookmarking WordPress stuff for a while, are they?