I want to learn a new web programming language but i dunno which to choose. I dont wanna learn one and by the time im finished its outdated

I want to learn one thats not gonna go anywhere for ten years or one that is new but is turning heads and will be the next big thing 2 years down the road. Just like what google maps did for ajax.

currently im leaning towards php as it so beautifully written and many huge companies use it (wordpress- joomla etc)

whats the best language to choose?