Another little feature request (along the lines of cleverer clippings) that for some reason is missing from OS X, even though it seems both obvious and trivial to implement:

Quick Look for plain text files.

Now, Apple claims that Quick Look works with nearly every file on your system, including images, text files, PDF documents, movies, Keynote presentations, Mail attachments, and Microsoft Word and Excel files , and it does work for some files (maybe those that end in .txt, although that would be very un-Mac-like), but most of the time I just get this: