The Roslyn Community Technology Preview (CTP) was released in October 2011. To help understand the significance and the promise of the Roslyn project, I've prepared a series of questions and answers. The questions are my own and the answers are based on my experience using the Roslyn CTP, along with my own research; but you can have confidence in the answers, as they've been reviewed for accuracy by Dustin Campbell and Kevin Pilch-Bisson of Microsoft's Roslyn team.
Roslyn is a CTP and there are many unfinished areas; it's not yet language complete. As a CTP, Roslyn includes features in C# that aren't yet available in Visual Basic, such as the C# interactive window, the C# scripting engine and the C# script code file format (.csx). That said, Roslyn is being developed under the principle of language co-evolution, so any feature seen in either C# or Visual Basic can be expected to be present in the other when Roslyn is released.