You can explore more in advance technologies of .net. As you are aware of MVC3, I suggest you to study MVC4 in which Web-Api template has been newly introduced. You can implement and see how it works. It is good to know that jQuery is already in your skillset, so you can use that also while developing any MVC application.
Apart from these, you can learn ajax, Microsoft dynamics,mobile development to enhance your skillset.
Wish you all the best!
I hope it is useful for you.