It looks like the N280 is not the next gen Atom, at least not according to a slide found over at HKEPC.
In this slide you can see that the N280 is simply a speed bin higher than the N270 (also with a higher FSB). But it is not a Pineview Atom.
The N280 + GN40 is nothing more than an "off roadmap" offering from Intel. It is probably been put in place to offset some of the damage being done by nVidia's ION platform.
By offering HD viewing and better CPU performance Intel might be able to hold off nVidia until it can get the Pine Trail - M platform ready.
Take a look at the slide