I'd like to be clever enough to emulate Cato the Elder, and come up with a short motto I could add to comments on all articles .NET related which encapsulates the following: MicroSoft, good work with the .NET Framework, C#, F#, and LINQ, but if you want to keep Windows relevant, make all editions of Visual Studio free and open sourced. That includes the Professional, Tester, and Architect versions. It's not enough to…
Why does the editor have to be open source? I think you might have an argument if you wanted .NET and other proprietary software related to development open sourced and available on all platforms but an IDE is not something that needs to be open source (though extensibility is always good).
2) Open source because MS still hasn't made it a good IDE for Javascript development. Yes it has Jscript Intellisense (nice), but you can't collapse Jscript by {} in the editor. This hampers it as a full-fledged web development IDE if you're going to do any more than trivial JS development. If it were OS, maybe someone would fix this.