Four years ago I posted about an idea of having the IDE (Visual Studio) do auto-conversion of your code from one programming language to another so give developers more language independence. I recognize that the only languages, perhaps, that would lend themselves to this are C# and VB.NET. They aren't completely equal yet, so it would still be difficult at this time, since each has a few features that the other doesn't.
Just imagine being able to open any solution within Visual Studio, and be able to edit it in your prefered language, no matter if it's originally written in C# or VB.NET. You would no longer be required to memorize syntax and feature differences between both languages; the IDE would convert it automatically for. This would reduce some of the issue of needing to bring in new employees or consultants that are familiar with one language or the other.
Also, this doesn't seem to be that far out of reach, even how the languages stand today. The main thing that would need to be written would be a compiler that compiles VB.NET to C#, and C# to VB.NET. It could contain some heuristics that could gracefully convert ceratin language specific features to their equal equivalent in the other language and back again as needed.
Wouldn't this be awesome?