I have a Fujitsu U820 aka U2010, a lovely ultraportable, with a nice Atom Z530 processor in it. The only shame was the use of GMA500. I had the pre-unity Ubuntu Netbook remix for a long time on it with LXDE and it worked well, I didn't upgrade because I had to stick with a kernel where someone had put in a lot of effort to get the official drivers that came via Intel to work reliably.
Eventually bit-rot set in and I had to upgrade, but the newer kernel and GMA500 driver was never as good, it wasn't much better than a VESA driver really.
So I am really hoping that there will be good useable driver and I can breathe some life back into what is still quite a nice device.
I wonder if the reverse engineering and work being done on the Atom stuff will help the ARM SoCs that have the same PowerVR core...
Sure, the SGX bits are probably similar or identical, but gma500 isn't split up properly so you cannot just stick it in another driver. Well, the MMU and blitter code is pretty self contained. But the modesetting bits would need to be rewritten for the SoC you're targeting.