Giving away Windows 10 and now this ... what is the endgame?
I think the endgame is to sell cloud services to the widest possible market, and extend Powershell and Windows Server into that management space for heterogenous networks.
In my opinion... Microsoft's survival as a technical and commercial leader.
Ballmer took Microsoft down a deadly road for far too long. The Board finally bounced him, and it's a damn good thing.
Microsoft could have done their products, their users, and their stockholders a big favor by keel-hauling Ballmer 10 years ago when he was busily making an ass of himself and a travesty of his company's reputation, by doing insane things like calling Linux a "cancer" and trying to wipe it out with SCO as the stalking horse, and later by not taking the first iPhone seriously.
Time will tell whether Microsoft's massive ship can be turned around in time to avoid the dead end, but so far the indications are pretty good.