I have discovered nothing so far that does for video, and audio for that matter, what Lightroom does for photography. Aperture can handle video files, but I don’t think it’s quite what the doctor ordered. Er, the professor.
There are two applications mentioned in a recent thread at Ars Technica that look promising: Usher and Clipstart. Usher looks more sophisticated, but both apps probably deserve a test drive. They are approximately the same price: Usher is $35 and Clipstart $29.