Honestly I have been worrying about MS for a while now. The decisions they keep making are (Seemingly consistently) terrible, and even worse is the fact that Apple and Google are close to beating them at their own game.
All that needs to happen to wipe out MS in 10 years is:
-Android gets a proper desktop OS with full PC hardware support. This will eat up the cheap laptop market.
-Linux gets full gaming support. This will eat MS's DIY PC market.
-Mac makes more mainstream models with even more supported software and games. There goes the mid-premium basic user.
All of these things are starting to happen right now with the exception of Android (Which is silly because it would be so easy to do and make a ton of money!) MS could easily save itself by focusing on what it does best and halting the money burning party that is the Xbox and Windows RT.