Everyone else here who said, “Keep learning” is right on, but don’t forget to work on your soft people skills along with your tech skills. Whether your long term goal is to stay in development or some other aspect of the industry, you should be comfortable talking to all sorts of people (management, sales, customers, etc…), making presentations, being social at conferences and so on. We (techies like me) tend to forget this, but it’s really important.

Imagine yourself starting your own company in five years or being the senior manager of a large group. How are you going to like meeting new people every day, selling or at least explaining your product or service to them? If the answer is “not very”, then start working on that now.