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 Missing Note
Play the level until you reach a dead brute who had a gravity hammer and near it is a dead marine who had a SMG. Above the marine is an opening in the wall. Go into this opening with your flashlight on. On the ground you will see a MISSING note. It appears to be a bungie employee (Jason Jones) that cannot be found.