Asus' Eee PC 1215N
might be considered to be the ultimate and most powerful netbook, at least judging by the specs that have been detailed at EeePC.it. Packing Intel's 1.8GHz dual core D525 CPU and Nvidia's ION 2 with Optimus support, this looks like a netbook that can easily outperform a lot of cheap notebooks.
Full specs of this 12-incher include the noted Intel D525 dual core CPU clocked at 1.8GHz, 12-inch 1366x768 screen, HDMI output, Bluetooth 3.0, 802.11bgn WiFi, 250/320GB HDD with 500GB of Asus WebStorage and even USB 3.0, all in a 1.4kg heavy chassis.
The new 1215N is rumoured to show up sometime in September, while the availability date, battery and the price are still unknown, although the latter will depend on the region.
You can find more info here