While I do wish the kids would go outside and play, it's not minecraft that's the problem, it's just the way kids are in the time of "playdates". Minecraft however is such a great game for them. It basically replaces the hours I spent with lego. I find hardcore first person shooters psychically disturbing so I'm greatly relieved when they find shooting sheep with enchanted diamond bows or building cat fountains amusing. Its similar to the way I used to build lego things that I could smash. Even better with things like raspberry pi, you can write in your own python code to build stuff or launch other people in the air when they come into your house.
The very best feature of minecraft is that there is no objective at all. Again like lego. it's up to you and your imagination. It just gives you an organized platform for creating.
What will MS do? I was afraid they might shutdown the python API on raspberry pi but they just released Windows for free on the new raspberry pi, so it looks like they might embrace it even more. I think Microsoft is finally re-learning how they became successful by being the low cost alternative to apple and IBM. they want the love again. Market share uber alles.
I suspect they might pervert it the way lego has been perverted by selling specialized kits that just build one thing. So they might sell pre-built minecraft worlds with various happy-meal like themes. Or hook it into microsoft live where you gotta pay the man a subscription to live in the microsoft amusement park. I would really resent that because kids come and go from their toy interests and so a subscription for something they are not using would hurt.