VOIP systems are here to stay. In America, the few big carriers can afford to upset their customers by blocking certain data traffic. But that would be the exception. Here, I think it would probably even be illegal.

I am assuming what Microsoft is doing, is something akin to what Spotify did. Pee on free users and gain a larger paying subscriber base in the process. Less traffic, more income. Win for Spotify/Skype, Win for competitors that want more users. Or want to sell phones with non-crippled software.