Last weekend I was working on a MVC 2 application. When I started the application my default browser (Google Chrome) came up. I actually wanted to change my browser for this application to Internet Explorer because the connectivity between IE and Visual Studio 2010 is much better than with Chrome.
The problem is that you can’t choose for the option “Browse With” in a MVC Application. This is because the controller is deciding which view should start. To fix this problem, I found an add-in for VS2010 that you can switch your default browser on the fly from your toolbar. In that way, you can switch easier between your installed browsers. See the screenshot below. 
You can download the add-in by following the link below.
http://visualstudiogallery.msdn.microsoft.com/en-us/bb424812-f742-41ef-974a-cdac607df921
Update:
If you get a popup on the startup of your Visual Studio Instance with the text: “The bits have expired, please download an updated version from http://www.wovs.com”, you have to download the new version. To do this, follow the steps on this website: http://blog.wovs.com/2010/10/how-to-update-currently-expired.html
Search in the online extension manager for “Default browser switcher”.