"They're going to use whichever video chat comes built into their SmartPhone, tablet, computer, etc. They're going to use FaceBook's eventual video chat service or something Google offers."
Really? I'm thinking the barriers to switch from Skype are pretty high due to the vast amount of users Skype has. Why switch to a slightly more polished product when you have no one to communicate with there?
We have to remember that the Hacker News crowd probably represents early adopters. Most people will not be as quick to try/switch to new services.