A couple weeks ago QTFairUse was ported to iTunes 6. Yes, it was just in time for Apple to release iTunes 7, but it looks like it’s also working at least for on music purchased with iTunes 7 as well.
Unfortunately, it’s Windows only (and still a little unstable I gather), but hopefully this means JHymn will soon be updated to work on the latest iTunes. Then maybe I’ll actually start purchasing from the iTunes Music Store again…