All the great new features of ASP.NET and C# aren't exactly new, but Microsoft have created a genuinely fun platform that a lot of people are starting to use outside of the famed "stuffy, corporate environments".
We use it at a digital agency and it's been fantastic. I'm a big fan of what both Python and ASP.NET are doing at the moment, and although I have tried Ruby and Node.js I really couldn't see myself wanting to use them for a real project.
To the best of my knowledge, stuff like PEX is new outside of academic environments. Moreover, it's highly non-trivial. Here is a collection of other interesting projects from their research department:
We use it at a digital agency and it's been fantastic. I'm a big fan of what both Python and ASP.NET are doing at the moment, and although I have tried Ruby and Node.js I really couldn't see myself wanting to use them for a real project.