The Intel Poulsbo Linux driver is a bloody mess, it's that simple. Unlike the main Intel Linux graphics stack, the one that supports the Poulsbo chip found on many Intel Atom-powered devices, is closed-source...
Great news indeed! Such a shame that Intel was of no help at all. Unless Intel steps up to the plate and at least maintains/updates the Poulsbo driver, it will eventually fall behind and into disrepair.
I used IEGD drivers back at times of the 855GM notebook chipset (= completely different). Though it's painful to configure/install these, they provided me some features other drivers didn't so I was kind of happy.
The Ubuntu-sourced driver has the same features, and is somewhat newer. I have never worked up the energy to try IEGD given that it comes in a 100MB+ _Windows executable_ (guh), but I don't think it provides any features the Ubuntu-sourced driver doesn't.
So Poulsbo users are okay for now with Fedora 11, but once Fedora 12 comes out they will be SOL because there are going to be no updated drivers for Ubuntu 9.10. Is that correct?
No one knows 100% (the Ubuntu statement on the issue is rather more ambiguous than it was reported as being), but that's the most likely outcome at present, yeah.
It's possible we may be able to hack up 2D support for F12 by patching the kernel and X driver components, but 3D and video playback acceleration wouldn't work unless Intel / Canonical provide an updated package for the proprietary X lumps. The situation's a bit complicated, also, by the fact that Fedora 12 and Ubuntu 9.10 may not use the same X server (may wind up with F12 on X server 1.7, but Ubuntu still on 1.6).
I may wind up having to forward port X server 1.6 to Fedora 12...