How much PC gaming is important to MS? I should be not very important they preferred to realese a console than push PC gaming...

It gives them to battlefronts to fight from, and there are many people that will never leave PC gaming...

And it is probably profitable as it encourages machines upgrades and therefore more sales of Windows.

Its only really important to them insofar as to keep Direct x relevant as they are developing Direct X compute for all the general purpose GPU stuff and they want that language to win as far as I can see.

It keeps people from switching to a Mac, and it makes people want to upgrade frequently which equals higher sales for Windows.

Microsoft doesnt really have ANYTHING to do with PC gaming at all. So really it doesnt matter to them at all.

Well it should have some importance, i don't know. DEV don't pay to MS to develop  windows games?

Developers dont play Microsoft a dime for PC game sales.

It what pushes their software off the selves.

Its mostly about DirectX at this point. Their game studio(s) rarely develop for or have much to do with the PC format.
What will the solution be for the new Google OS I wonder, in terms of 3D accelerators? MS certainly won't let them implement DirectX, will they?

no, but OpenGL works great.