They'd need more than to open source it, I think. For .NET to make it, they would need some kind of killer app -- something that makes people use .NET despite whatever natural inclinations they may have. I don't see that happening.
I mean, ten years ago, did you think lots of people would be coding in Objective C? It's funny how things change.
> For .NET to make it, they would need some kind of killer app -- something that makes people use .NET despite whatever natural inclinations they may have. I don't see that happening.
By "people" do you mean developers or end users? Because if you mean end users, every end user of Windows uses some program that's built in .Net every day. End users don't care, as long as it works.
If you mean developers, developers go where the people are, for better or worse. There are a lot of people using i-devices, so Objective C lives and will continue to live. There are a lot of people and companies using Windows machines, so .Net lives and will continue to live.
Only thing I can think of that might save the day is if MS properly open sourced it. Chances of that have to be pretty much identically zero though.