Intel Atom SoC graphics have historically been crippled by their use of Imagination PowerVR graphics, which aren't covered by any working open-source driver and the closed-source PowerVR drivers are generally notorious on the Linux. The situation has solved itself though going forward in that with Bay Trail and future Intel Atom platforms their graphics cores are derived from in-house Intel HD Graphics that are supported by their high-quality mainline open-source Intel graphics stack.
For those that are stuck with some old Poulsbo era hardware, the mainline DRM/KMS driver is at least working towards 2D acceleration. The GMA500 driver that was started by Alan Cox when at Intel is now receiving contributions by Patrik Jakobsson.
In a set of eight patches published on Monday to the dri-devel list, there's prep work for 2D acceleration with the GMA500 driver. Patrik wrote, "In order to do blits on GEM buffers we need to enable the MMU. The MMU currently mirrors the GTT in a single MMU context. We also need GEM buffers to handle base alignment restrictions for various buffer types. For blitter debugging, GPU hang recovery and blitter status we also need to handle SGX interrupts. The old ioctls can go since nothing ever used them and they don't do what we need. These patches should be totally transparent to users."
If you were hoping for 2D acceleration to happen for GMA500 in the Linux 3.14 kernel, that's not going to happen as this is only prep work and there's still a lot of code to happen first of all. This prep work wasn't even submitted as a pull request for 3.14 but is just surfacing now in patch form.