While the task to keep current is daunting, there are some things you can do to keep fresh, and balance your skill set. Here’s a brainstorm on ideas to help you keep current :
Take some online courses in areas where you have interest. There are some very helpful and free solutions for Dot Net developers at MSDN. I have a buddy who has found an lot of success with CodeSchool.com for learning mobile technologies and web development techniques.
Sometimes you have some flexibility in projects you are working on. Use a new framework, rather than the one you know, to become familiar with the differences.
Build a network of others around you. Share the load of building expertise. There is too much for any one person to learn, unless that is all you are going to do in life. At some point you have to stop learning and start billing.
Complete a certification. I have found this is a great way to expose areas of which you are not even aware. Even if you don’t take the tests, at least you are exposed to knowledge the vendor deems important in order to use their product.
Join a user’s group in your area. Participate actively in the group. Give a presentation; then you’ll have something you are sure about.
Cheers,
Ben