John,
You're not alone.
This has been on the to-do list for awhile, it's just a matter of coming up with a cogent UI and an efficient algorithm for performing the pattern matching during the capture process.
As a hack, it's
sort of possible to do this now using the
qrecall command line tool. You can use the tool to set the capture preferences for a file, and you can use the shell script to perform the pattern matching. Thus, it's possible to execute a script like this to manually mark all *.mov files your Document/Projects folder so that they are never captured:
find ~/Documents/Projects -iname '*.mov' -print0 | xargs -0 echo qrecall captureprefs exclude
Of course, this isn't dynamic. Every time you create new *.mov files you'd have to re-run this script to mark the new ones, but it's better than nothing.
I should also note that many modern applications will correctly mark intermediate files (rendering cache files and so on) using OS X's "do not back up" setting. If you set the archive's "Exclude items excluded by Time Machine" option, QRecall will honor those hints and automatically exclude those items.