The Skype protocols are already proprietary and not published (I haven't checked if they're patented). It's not like Skype is an open standard or anything. This

The Skype protocols are already proprietary and not published (I haven't checked if they're patented). It's not like Skype is an open standard or anything. This is one company that sells proprietary products buying another that sells proprietary products. Microsoft would be stupid to kill Mac and Linux support for Skype (perhaps they may kill just Linux support). The value in a communication technology is in how many people can use it; the more people who are on it, the more it attracts. If they start cutting people off, it will become far less appealing for anyone to use, and very easy for a competitor without such restrictions on their network to steal customers.