I think the release of Halo 4 is a good opportunity to add some new features to Theater mode, seeing as there weren’t any for Reach. It’d be great to be able to set up camera movements (like in Black Ops, only without the annoying floating cameras), and if possible, add some more advanced controls such as adjusting the focus. What other features would you like to see?
Rewind would be nice. I also want to view with friends again.
I wouldn’t mind a filter system like we have in forge.
I want for Halo 4’s forge to have rewind and I also think that you should be able to take bits of different films you have saved and put them together so that you can make your own montage in-game.
a feature letting you upload videos straight to youtube, like you can in dirt 3 
Party viewing, scoreboard screenshots and a flexible third person camera that doesn’t suck.
Fast forward skipping, like how we have with rewind skipping.