I was reading the Nikhil's home grown project Script# which compiles .NET code as Javascript code instead of compiling it to IL code. Amazing work!!.
The same day google as well released an application which they call as Google Web Toolkit (GWT) in JavaOne conference.
In my view, both are great tools that will ease writing JS. It will avoid the time spending in writing JS scripts directly, which is toughest process when it needs to be debugged. Anyways, Nikhil's project is a kind of pet project and it is in very early stage. May be MS will soon commericialize it and put more effort in making it in good shape.