I'm having this issue in Visual Studio where it hangs when editing the knockout binding in a razor view.
I've raised the issue on Connect (http://connect.microsoft.com/VisualStudio/feedback/details/780015/visual-studio-2012-hangs-when-editing-knockout-binding-in-razor-view) and included a small sample solution that enables me to reproduce on at least 3 machines (two at work, and one at home).
I just wondered if anyone else has had this issue, and if so is there a workaround. For us, one of the main benefits of 2012.2 is the knockout intellisense, but this is a no go for us at the moment.
Sam