Umm... a pair of these things HAS to cost in excess of $4000-5000, don't you think?
As you said, up to 6 gigs. The 6 gig version will be expensive, but they'll have cheaper options with less expensive GPU.
2. The PCIe flash drive in the Mac Pro that's "up to 2.5x faster than current SSD technology"? Again, sounds costly! The only similar drives I see for sale already in the Windows world are models like this one
Don't forget the freshly updated Macbook Air, it has a similar SSD that has reads and writes in the 800 and 700 meg per second ranges.
No way this thing starts out costing thousands more than the previous version. Probably a price increase of $500 tops, and I think there's a good chance it's even less.