I think the problem is that there simply aren't enough companies interested in it to make it a viable proposition. It's not more for me but there's not doubt that the Surface Pro has some clever technology and solves some people's problems brilliantly. And it's probably much better as notebook replacement than an I-Pad is. But the PC market is about massive scale with significant penalties if that can't be achieved.
Microsoft has the cash to continue with the Surface Pros, after all what's 1 billion compared to amount spunked on Nokia, Skype and Minecraft? But it's not doing them any favours with the dwindling number of OEM partners that make its market. At some point Microsoft will have to choose whether it wants to do an Apple and be the sole supplier or return to doing just the software.
Biting the hand that feeds IT
