When NVIDIA unveiled its Optimus battery saving tech a while back many were really excited by the prospect of more run time from the battery and GPUs for multiple needs inside a computer. When Next Generation Ion came around from NVIDIA many though that the new Ion platform and Optimus tech were mutually exclusive.
A rumor is going around that the Asus 1201PN netbook that will be using Next Generation Ion will in fact lack Optimus. That would presumably mean that the machine would have only the NG Ion GPU inside.
This is certainly a rumor for now and there have been no official confirmations from Asus or NVIDIA that the machine will not use Optimus. If true, this could be a cost saving measure to allow the 1201PN to appeal to budget shoppers.