Sneaky Peek into the next release: EMGD
Intel released a new driver compatible with GMA500 (a.k.a. poulsbo, psb) called EMGD, i tried it for you (and for me :-D)
PixieLive-1.1alpha + kernel gentoo-sources-2.6.33-r2 + xorg-server-1.8.2 + EMGD
it run quite well, really smooth on 2D but 3D applications (glxgears) freeze the system after some seconds (mouse cursor is still moving around, but the system doesn't respond)
so... gotta find a solution...