Please don't take this pejoratively, but Microsoft hardly ever, in the thirty years I've been watching, taken the lead in any "new" iteration in IT. Instead they are quite adept at watching from the sidelines, learning the steps, and then slide in as a new dance partner. It usually takes a few iterations before Microsoft is in demand as a the foremost dance partner. [Embrace, extend, extinguish to Microsoft-bashers.] What they turn out is turn-key technology especially when you mix in their partners and developer bases.
Devices and Services seems to be the new dance-craze and judging from past results, Nadella seems to be the right lead. History will make that judgement. I do have a couple of concerns with the activist section of the Board but not knowing all the players, I'll reserve likely hazards aside from observing that the $40 Billion stock buy-back is poorly timed for a company investing in a "newish" sector. Perhaps that was the "price" to keep them at bay.