Sure, DotA can be just attack and defend, but I can assure you that there are reasons that game balance, map balance, and item balance is an issue in DotA, WoW and other level based pvp games. It's that good players will find strategies to exploit the system to give them an edge. So simply saying that it's easy to create a DotA style map and not put thought into the above mentioned will most certainly yield a bad gaming experience.

In any good game, you have to address the possible strategies that players will come up with, or the game will just fail.

btw, dota is not just picking a path and going with it, the fact is people move around the lanes a lot and that is what keeps you on your toes. It's only in the early game where you see people staying in one lane. The fact that it is a team game also negates the statement that it is just attack and defend. It can be thought of that way if it were a single player game, but it's not. There's three lanes and five players. I mean, if you're not in a solo lane, you're in a double lane trying to manage exp and gold distribution and trying to find opportunity to kill the opposing person in your lane (or even killing someone in another lane for that matter). Considering all the variables of teamwork, it's about timing, sound strategy, and adjustment.

And anyway, I'm not opposed to having a new BG, or creating something different. I'm just saying that trying to mimic DotA with the WoW mechanics is going to be much more difficult than people think it is, and instead of trying to recreate DotA I would suggest trying to create something different altogether.

There's a reason DotA is so popular and fun. It's unique, it's deep in terms of strategy and skill level, it requires communication and teamwork, and it's highly competitive. Since everyone starts at level 1 at the beginning of every game, DotA players don't strive to progress in items and levels, they strive to gain in ability and skill. WoW BG's should focus on those characteristics rather than recreating the actual mechanics of an entirely different game.

Sorry I'm so verbose, but that's how I roll. :)