Honestly, I can see ATVI’s position. It doesn’t seem as one sided as many people are making it out to me.
You have chosen to register a name that is exactly the same as the common name of the game, only one hyphen different from the official site, and you make no effort to tell people that it isn’t the official site. It may be there somewhere, but I don’t even see a link to id, SD, ATVI, or the official enemyterritory site anywhere on the first page. Nor is there anything that stands out saying it is a fan site. Regardless of whether you are legally in the right, you have certainly failed to show common courtesy.
By registering a site that is so blatantly close to the official name, you set your self up for conflict. You should have realized this when you registered it.
The site is also full of invasive adds, which gives a bad impression of the product to anyone who thought it was the official site. The fact that you can block them is irrelevant to this.
edit:
I should add that I’m not trying to say ATVI should take the domain. It would just be bad PR for them and not gain much of anything.