The Microsoft RDV team have published a new blog post on RemoteFX vGPU improvements in the R2 release of Windows Server 2012.
The blog post covers the following four improvements in great detail
1. Improving DirectX API coverage
2. Support for higher monitor resolutions and higher default monitor resolutions
3. Exposing higher VRAM to RemoteFX vGPU-enabled virtual machines
4. Higher scale by leveraging NUMA in Windows Server 2012 R2