Well gaming netbook is a bit of a misnomer as these things are not exactly cheap. Still it's a gaming laptop in a netbook chassis.
Alienware seem to be the first to bring a proper will actually run games netbook rather than the it'll run stuff that's 20 years old if you step the resolution down by a few notches previous efforts have achieved. It also incorporates some new technology designed to make this platform work better. It essentially has two graphics cards one onboard low power intel one that you use the bulk of the time and an nvidia G335 which takes care of gaming and probably hidef decoding it can switch between the two at the touch of a button no need to reboot or any of the niggles previous attempts at this technology have needed. It allows you to get something like 8 hours of battery life for normal operation and then 2 or so if you switch on the graphics card (which from bench marks will handle games in 720p at a respectable framerate).
It's an interesting development and this is probably the first of a wave of such things so hopefully they will get cheaper this is currently 700 quid for the base model. Still this sort of thing seems like it's perfect for things like con's a machine that can run modern games that's 11" diagonal will fit in a small ish backpack a lot easier to cart around than a full machine.