Here is an interesting comparison of Cortana over the course of the 4 halo games:
PTesh adds his dulcet prepubescent tones over the top of one of the new trailers for weapons...
Try upgrading your browser to Google chrome (you wont regret it). There is probably an IE...
Hidden flood battle
Right at the beginning of the level by the turret look around to the left of the hill, you should spot a battle that doesn't seem to serve any other purpose to the gameplay other than being a cool little egg to find.