What the Hell can .Net do exactly?

What's an example of a possible application that can be made with .Net?

What's a current example of an application using .Net?

One problem with gcj is that the resulting executables are slower than most JITs.

As for expressiveness, Java isn't particularly expressive. It's the COBOL of the modern era. Nor does expressiveness have to come at the price of speed - witness certain dialects of FORTH and Ocaml.

Java could have been a whole lot better if they didn't make such a mess of the libraries. The language itself is just fine.