[duckpunch]

You should be careful in thinking that you have to choose. In fact, regardless of what you do with .NET, I think it's a good idea to learn about the *nix environment and some languages that you're not yet comfortable developing in.

In my program at school I see a ton of students leaving university knowing nothing but one to three statically typed OO languages, and assuming that those paint an accurate picture of the full range of programming languages.

I'm not saying this is you, but if you're not comfortable outside of C#, Java, C/C++ etc. you're limiting yourself. Programming languages may be difficult to master, but you can glean a surprising number of lessons from one language by spending a few weeks with it. I think a few languages a year isn't asking for too much, and whether you use them or not, the lessons will transfer to the language you spend most of your time in.

If all of your programming experience involves using IDEs, do yourself a favor and spend extensive time in a powerful text editor like vim or emacs. While these editors might not have the advanced features present in IDEs, making the trade in favor of a more powerful programming language used in concert with a less powerful editor may actually make you more effective. The point is that you can't discern between the two until you've spent ample time in both. Being uncomfortable outside of an IDE can be a serious crutch as it keeps you using languages that the IDE can take full advantage of, and this excludes a number of languages that you should expose yourself to.

Nosql is an orthogonal issue. While relational databases are unlikely to ever go away, if nosql databases continue seeing success, there's no reason to think that seasoned .NET folks won't also make use of them.