I had e-mailed iTunes support because I wanted to inquire about re-downloading some missing content due to an AppleCare HD replacement. They had e-mailed me stating that they will make this one time exception and let me redownload my entire purchased library. All I had to do was go to advanced options, and select "check for purchases." As I am downloading my videos, even some purchased at the beginning of the year, I noticed that they are all now in the higher resolution 640 by whatever. I'm sure all of us would like higher resolution videos so we can enjoy them on our upcoming iTV boxes, so I thought I'd pass this idea to you guys. Please do remember that Apple only does this once, but you will basically be getting a fresh start. Just e-mail iTunes support and tell them that you lost all of your content due to a hard-drive crash, not just simply because you want higher res videos. Good hunting.