Open your WoW directory from Programs, open the Cache file, you should see the BackgroundDownload.torrent file (if you don't see, simply start the game up, let the background downloader begin, then stop it, it'll appear then).
Now just open that file with a BitTorrent program (I use UTorrent, as was suggested on these forums and it works magnificently, very user-friendly, as well), point it to your Patch folder in the WoW directory and voila, it's as easy as that, boys and girls.
Keep in mind, this will let you download the patch (very quickly, I might add, 45 seconds for me) but it will still need to be installed via the Updater once the patch is officially live.
As an aside, I'd like to thank Shmii (I believe it was she) for enlightening me to this method of obtaining patches, I was always forced to wait for patch mirrors previous. No more Filefront for me, Thankee-Sai.