I agree with ZS. Learning to think in a programming language and understand the basic constructs is the most important part. If it happens to be a language that is widely used, bonus, but anything that is user friendly is even better. For younger kids I especially wouldn't get too hung up on it because things change.
The first language I learned was obsolete when I took the course in university (they switched everything the next year to C/C++) but it introduced me to all of the concepts enough that I was able to figure out C/C++ in second year. I've used 12 languages in my professional life (which spans hardware, software, firmware and various scripting languages) and there are more similarities than differences between them. Each language has it's own quirks and tricks but for kids starting out it is about learning the concepts of if statements, case statements, goto, repeat, for loop, etc. Those are the basic building blocks for everything else.
