jps, really great to hear that you are taking HCI guidelines into account! (But I'm an interaction designer - I may be a bit biased as to their importance ^_^)
I'm not sure whether this is the right place for a wishlist, but it'd be great to be able to match path names as well as file names in the project pane. I work a lot in Symfony (PHP framework), where a lot of files have the same name. Under every module (which is a simple directory), there is a file called action.class.php (containing all the actions that the module can perform). So I find myself in a situation where I'd like to be able to match a bit of a directory name and a bit of the file. I'd like to be able to type "google act" to filter out all paths where both "google" and "act" are not present.
However, maybe I should just look into building a Symfony aware plugin once Sublime X is released.