Going back to Intel G45 and newer graphics has been a "BSD ring buffer" for H.264 and VC1 VLD decoding. All hardware up to now has had one "Bit Stream Decoder" ring for video decoding, but with the high-end "GT3" graphics of Intel's upcoming Broadwell hardware will be two rings. Broadwell GT3 (the highest-end graphics) will have two independent decoder rings for processing video commands. For the upcoming CPUs featuring GT3 graphics, this should mean a faster and more pleasant video experience, particularly when dealing with multiple video decoding streams.
Confirmation of the dual Bit Stream Decoder video rings is confirmed by Intel's latest Linux kernel patches. These Intel DRM patches are still outstanding and thus will not be merged until at least the Linux 3.16 kernel.