Inbuilt console for scripting code against current projects / libraries.
It'd be awesome if we were able to rapidly prototype / test class libraries / methods without debugging or creating test projects / unit tests. I.e. create a new interactive command window similar to the Python interactive window but for .NET code which can then be used to rapidly test methods and routines in the current solution.
It should then be able to export the script code to be included as a new unit test under a specific location in the current solution.