The streaming music apps are due to licensing issues. It's a big, big mess when dealing with licensing of streaming music and can get VERY expensive. The app I worked on was going to be US only simply for that reason. It gets a lot more complicated and expensive when you open it up to other countries. Especially with an app like Pandora where everyone isn't listening to the same thing at the same time. If someone with the popularity of Pandora opened up their site and apps to everyone around the world they'd be looking at millions of dollars a month in licensing fees alone, not to mention the bandwidth and hosting costs. That's part of the reason they were going to call it quits if the new licensing pricing model was approved (which it wasn't).
Just curious, does the Pandora website work in Canada? Or is that blocked too?
And Skype is due to some legal issue, Skype issued a statement about it.