Once ATI launches its dual RV670 board you can expect it to be available in sufficient volumes. This is the plan, and if ATI wanted to launch a limited number it was able to do that back in December.
The samples are in good shape and the hardware was finished back in December, but we are still waiting for the final driver.
This is a tricky product, as some games will scale really well, but some (including Crysis) are much more unfriendly to the dual card; and ATI wants to make sure that it has the best driver possible when it launches this card. The plan is to introduce them in late January.