1720 comes with Intel C2D and 1721 AMD. I would assume the Vostro to be the special edition, maybe XPS replacement.
Spec wise, all the Santa Rosa laptops are pretty much the same. It boils down to how refined Dell with make theirs in light of their poor financial performance vis a vi HP. The buttons on the front indicated that there are no touch sensitive adjustment ala HP. I hope they've graduated the 3+ year old design to one with:
- dual HD Raid
- SDHC slot
- HDMI or better yet
- Dual link DVI
- keyboard with numpad (please get off the one keyboard fits all model design).
- built in flash memory (Robson)
- non fading palm rest
Seeing that we're going to be stuck with this 'new' design for who knows how many years, let's hope is a giant leap forward.