From time to time a buddy of mine will come over and he will log onto his acct through my xbox and we will play some MP together. Something that I have grown to use quite extensively is the kill feed to know who just died in what conflict. I am not sure if this is limited to the xbox alone, but it has plagued me and many times changed the way that I like to play.
I am not sure how you want to address the issue, whether it be a shared kill feed in the center of the screen or individual ones, but please get this fixed. It seems like an easy change to implement (though I admit I am no programmer).