During the last 10 minutes of Ander's talk The Future of C# he demonstrates a really cool C# Read-Eval-Print loop which would be a tremendous help in learning the language.
Several .NET4 related downloads are already available: Visual Studio 2010 and .NET Framework 4.0 CTP, Visual Studio 2010 and .NET Framework 4 Training Kit. Do you know what happened to this REPL? Is it somewhere hidden among examples?
I know about mono repl. Please, no alternative solutions.
The REPL demo was part of "what might happen next", i.e. after 4.0; in .NET 5.0 or something similar.
This is not 4.0 functionality, and never has been.