It's nothing like WoW as in they're two completely different genres.
It's like comparing CS:S to Starcraft2.
DOTA is DOTA. Defense of the Ancients, IIRC, is a mod to, Warcraft3, an RTS. I believe the genre is now called "ACTION RTS" or some stupid shit. They have to give a label to every game so I guess they decided to make that one up.
Yeah LoL may have MMO elements with the "Summoner" and "Mastery" features, but it isn't a traditional MMORPG, like WoW is.
Hope I clarified enough!