I don't know why people are fearing the game will have "generic" gameplay. Its not like it was not expected. I mean, it was never announced as a revolutionary game, with visionary mechanics and such. It was pretty clear from the start that they were focusing on a game that values storytelling and traditional third person shooter mechanics. People will only get disappointed if they set their expectations way to high (which I am sure will happen, as always).
I mean, I am myself expecting great things from the game considering RAD's history. Personally, if it something on the lines of an Uncharted game with superb graphics, solid gameplay and a well written story its going to be fine. I am sure people will watch the trailer expecting something like a new RE4 or something like that so its obvious that there will be overreactions and meltdowns etc... But oh well, nothing anyone can do really.