A: The only one I found is iTap Mobile. I purchased it and tested it, and it did indeed support RemoteFX and allowed the use of DirectX and other graphical applications.
However, it doesn't work well with Windows Server 2012 RemoteFX and Windows 8 RemoteFX yet. But since that product is still not released, that's not surprising. I would expect them to update with the latest RemoteFX support after Windows Server 2012 is released.