Comment Do or Die (Score 1) 772
Here is my $.02. If you don't stay current with languages, you may be able to find niche employment, but at some point, your fun will most likely end. Some languages are, of course, timeless (C++), but nobody in their right mind would choose to use VB or Delphi over .NET these days. My advice on languages is always the same: learn C++ first, then any C like language is in your reach. Learn C# or Java next, and JavaScript. With the three of these, you can do anything. Programmers who know C/C++ will always have an advantage over the new kids that started with Java/.NET. Any time something cannot be done easily in managed code (C#/Java), you will become indispensable (trust me).
Keeping a broad base of familiar languages can be a serious boon. At a single company, I have written things in C, C++, Java, VB, Delphi, C#, Ruby, JavaScript, Flex, Silverlight, Perl, Python, PHP, and old style ASP. You never know what will be thrown on your desk from new technology, or even (the Taliban ninja) acquisitions of other companies/technology. That is job security.