I would buy at least two more as well if these functions were integrated. As it is however I plan on achiving my DVDs. Does anyone know what the best way to add about 600 to 800 GB would be?
Definitely use some form of RAID 1 or 5. For the purpose of archiving large DVD files, a 3x300 or 400gb raid 5 wouldn't suffer badly on write performance, but would save you weeks of time should a drive fail on you.
I think appliance form would be better - let all your computer devices enjoy the space. Not sure there are any cheap solutions. The linksys LSLU2 only (easily) supports two USB drives, not enough for your needs.