I can see 'InstantAccess' being quite useful. On both Intel and AMD integrated GPUs the chips share main memory (and often a cache), so this extension may actually see use.
On top of that CPU/GPU integration is a major bottleneck in many applications and games, with a ton of techniques and tricks trying to get around both the bandwidth bottleneck and the latency. By being able to have both the GPU and CPU read and write the same memory can lead to very fast/tight integration and some really amazing effects that couldn't be realistically done any other way. Even in the case where it brings nothing new to the table, being able to submit smaller batches, or work with buffers in a more natural/dynamic manner will be nice.
On the other hand I don't see 'PixelSync' seeing any real use.