I\'ve run through the tutorial on this here: http://www.asp.net/vnext/overview/aspnet-vnext/getting-started-with-aspnet-vnext-and-visual-studio
I am following step 7
You are probably running with the debugger attached. The file watcher doesn't work with the debugger attached. Why? Long story short: IIS (express) is restarted to pick up assembly changes, so that would not work with the debugger attached because it would kill your debugging session.
Start the website without debugging, then change a code file and refresh - magic happens.
Later edit: To start the application wihtout debugging either use Ctrl + F5
or Debug -> Start without debugging