Apple chooses the hardware that runs their software to ensure the experience is consistent.
Microsoft, on the other hand, creates a software OS that needs to go with many different hardware configurations. Each hardware vendor needs a mini-microsoft team to sure that the hardware they are making, will work with the OS. Just as Microsoft outsources QA, I imagine these hardware vendors do the same. I think this explains the problems with windows, since the quality of the product varies from manufacturer to manufacturer (which is incidentally why MS started to put out their own hardware tablets).
Hopefully these MS stores will offer some kind of support for questions Windows users will have, but I think they will probably staff them with sales people that won't be able to help much with technical questions.