My first thought I remember I read that Cortana will make a big impact in the game, I think that maybe she will get a robbot body to Control as sidekick to the 117, but I rather have 117 to be the lone gun like in H1 and H2, and not like in H3 when the Arbiter joined up almost the entire game
My second thought is that all files in H4 Local files like movies, videos, pictures, maps and stuff are not like the REACH and H3 Local Files all in one place (hard to explain) I think that the music on your computer you have a folder and 300-400 Trax in all different types rock, RnB, teckno, it is difficult to find which one you're looking for, but if you have multiple folders named rOCK, RNB, tECKNO its easyer to find which one you're looking for. Bak to H4/REACH.
In REACH, I have exactly 488 films and videos, and it's so d * mn hard to find the right one (or map) that I would like to have folders in H4 Local files to sort things up with foulder name (maps) completed mapping, started new maps (movies) good game, my super sprees and so on and you can move the maps / movies after finished with them so they are not stuck on foulder you choose
and besides that i have no more request i think 343 will make hell of a good trilogy