Eilon Lipton has posted a migration tool for converting ASP.NET MVC 1 application projects to the soon to be released ASP.NET MVC 2. The tool takes in a Visual Studio 2008 project for ASP.NET MVC 1 and spits out a Visual Studio 2008 project for ASP.NET MVC 2. This changes the project type, updates and adds the appropriate assembly references, updates the generated configuration files, and adds the appropriate new script files.
If you want to upgrade the ASP.NET MVC 1 project to Visual Studio 2010 as well, you have to do that using Visual Studio after running the migration tool. The final version of Visual Studio 2010 will include a direct migration tool to avoid requiring two steps.