You're confusing C# with .Net.

There's a lot more to .Net than just the common language runtime engine.

A good chunk of the core is the interoperability present with web services. Which has nothing at all to do with Java.

As far as I've seen, Sun only recently discovered this was a great idea and jumped on board. That was shortly after Microsoft, IBM and the others announced the idea.

Giving Java credit for something Java didn't do seems odd.