It's so fun and so well made. Very great game, sadly it's in closed beta though. I haven't played LoL, but people who have played both told me DOTA 2 is much better. Anywho, I have 3 extra beta codes, anybody who wants in on the closed beta just comment and I'll send you a key. PLEASE only ask if you're actually going to play the game.
System Wars related: DOTA 2 is the sort of experience you can't have on consoles, it may be hard to get into, but it's a very rich experience that's both fun and competitive.