Why would they shut it down? US gets minimal revenue from regular phone calls, most of what you pay is sales tax. The industry has argued users pay taxes when they pay for their high-speed internet.
No way Skype or any of the VOIP units get shut down. There are countries which allow the local monopoly to cut off or block the connections, but these are mostly not working I have read. The biggest losses are for local phone companies in countries with ridiculous phone prices. If you get a modem programmed in the US with a US IP address the first time you use it, you can pack that baby up and take it around the world with you. Live in say Greece, but want a New York number for family? Just be sure you program the modem when in NY, but then you are free to use it in Greece after that.