On the other side of the coin programming, especially web programming, probably moves forward faster than most other professions. You may not need formal training again as the underlying concepts are usually the same but the vast majority would have to learn new methods and languages over their career.

I can see this happening in the near future with concurrency in programming, there is going to be a shift more and more towards concurrent programming where most popular languages and methods now will struggle and we will have to move towards programming in ways that the compiler can help us a lot more with concurrency as languages like Haskell have been designed to do.