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...
Halo Anniversary Terminals
Not much information has come out for this game yet regarding easter eggs, accept that it has been confirmed that all new easter eggs will feature in the game. The one new piece of interesting information that has been released is the addition of terminals, which will behave similar to the way they did in Halo 3.
Frankie has said in an interview that they will add new depth to the Halo story. Click "Read More" to see a sneak peek video of the terminals.