DDR2 is available in limited quantities from memory manufacturers, although there is no JEDEC standard for it and (of course) no motherboards that could use it even if you had it. It apparently didn't work out all that well for ATI, as they went back to standard DDR on the 9800XT.
2.2ns DDR (not DDR2) memory is used on all GeForceFX 5900Ultra/5950Ultra cards. I wasn't aware that it was on the 9800Pro 256MB, as the other 9800Pro cards (and most 9800NPs) use 2.8ns RAM.