I back KaliKoPoi's statement, "Learning a new language is not a piece of cake. Don't fall in IT trap just because you see someone making some more dough" .
I have seen many people making this exact same mistake.
As far as which language is popular question goes, there is no discrete answer. Personally I see that Javascript is becoming the major player among all. Javascript used to be a client side language few years back, now with server side programming built on top of javascript, everything is changing.