Challenged by a coworker recently, I created a simple add-in for Visual Studio 2010 to modify the settings for code formatting based on the file extension. The usage scenario is simple: allow for different language formatting rules based on the file file type (or extension). In this case, he wanted to have a different standard for curly brace usage in MVC ASPX pages overriding the default.
The documentation is here.
The settings he used for MVC pages are included in the documentation. If you have any questions or issues, either leave a comment here or add something to codeplex.