Why do you have Activision Publish your game? I am pretty sure you could of gotten ANYONE to publish such a hot property as Angry Birds. Capcom, Ubisoft, Majiesto, Warner Brothers, EA even, somebody BESIDES Activision.
Or, an even better question, with all the cash the Angry Birds guys have, why do you NEED a publisher? Hire a lawyer to deal with all the mumbo jumbo of becoming a publisher, use your own money to fund it, and then get 100% of the profits. Ok, what ever profits you made after Finlands high taxes (nordic country and all the jaz) but still, the game has been calculated to of made 70 MILLION dollars alone, and that is not counting the massive merchandising deals, the sequel games, and all the appearances in ads. The game was REALLY cheap to make, costing about 140 thousand dollars. I am pretty sure just boosting the graphics to HD doesn't cost so much that you needed a publishers money.