The majority of jobs with newer companies or even newer projects at larger companies tend to involve C#, at least in my city.
For startups developing in Java is probably not a great idea, because startups need to respond to change fast and get things up and running fast, and languages like Python, Ruby, some kind of LISP are way better at that. You can always re-write your application in Java/Scala if performance/scale becomes an issue (a lot of startups dream about having those kinds of problems :D).
The perfect combination would be a dynamic language for the web server that calls a java based web service for most of the functionality (Jersey rocks)
See this: http://channel9.msdn.com/posts/C-and-Beyond-2011-Herb-Sutter...