http://nodejstools.codeplex.com/releases/view/104141
https://www.youtube.com/watch?v=ZAroJmb6XY4
It was in the original title, but has been edited out.
1) "Set Next Statement" doesn't work, which is a pretty big part of E&C
2) I could change code and literals without stopping and restarting the debugging session. Each change causes the current statement to jump to the top of the current function, or to the first line if modifying code outside of any function. Local variables are reset, but globals retain their state.
3) Interestingly, I could change code in a function that does not have the focus, and nothing is reset, then step into that function.
I remember seeing something similar when V8 was being demoed and showed a "live edit" capability, so I guess NTVS has similar functionality.
It short, it sort of works, but it's not the same as E&C for .Net (C# or VB), C/C++ native code, or Office VBA.