From Eric Lippert's blog posts about this, the Roslyn project most definitely doesn't seem like a one-person-getting-inspired kind of thing. I was talking to a guy in the Roslyn team last week, and the project scope, and the way they have decided to implement it, is quite frankly astonishing. I mean, a dynamic parser/lexer with all the underlying data structures immutable [1]? Impressive.

[1] http://blogs.msdn.com/b/ericlippert/archive/2012/06/08/persi...