My feeling is that long term, Microsoft will become less and less relevant to anything. Look how they missed the boat on smartphones. Everyone is getting along just fine without them. They seem to be set to miss the boat on ARM servers as well, and I really don't think they will be missed there either.
"And we are still waiting to hear anything about Windows Server for ARM."
ARM servers are of most interest to big cloud data centers. Cloud infrastructure is largely open source and Linux based, and doesn't care about the architecture it runs on.
The success of ARM in the server space has very little to do with Windows Server.
Frankly, I don't now if the CUDA vs. OpenCL was answered at GTC this year. As GPGPU based computing is gaining prominence in CAE/CAD/EDA tools market, developers of simulation tools seemed to be left with a choice that nearly doubles their effort in code development.
Rick, regarding "...Google has been mum on any plans for Android in notebooks..." -there is Android's daddy on notebooks today...Linux! I am skeptical about Google taking on M'soft on OS's for notebooks, in light of Windows8's success(?) so far! If touch-based computing is the determining factor, it may very well be that Windows8 and beyond will prevail on notebooks (assuming that notebooks will exist in the future!).