http://www.phoronix.com/scan.php?page=news_item&px=OTg1NQThe Exynos 4210 is used in the Galaxy S II among others. This is the first open modesetting driver for an ARM gpu; while it does not do 2d or 3d accel, it is a step nobody has taken before.
With this, one could use Xfbdev for an unaccelerated X.
Let's hope Samsung brings open 2d and 3d accel too.