League of Legends?

Not too sure what to think about this game. My friend recommended me playing it, but idk if it's worth the time. it's appearantly based off a Warcraft 3 custom game type called Dota. It's in a whole seperate genre by itself called action-rpg, or something like that. I was wondering if anyone has played it, and their opinions on it.

If you have not played the game, here is a link;
http://signup.leagueoflegends.com/?ref=4e079bf6649fa447093978