Something that was in the original 2.0 concept picture, but I haven't seen in any of the actual 2.0 screenshots, was the ability to see enmity for other party members. As a tank it's handy to know how much enmity you have compared to everyone else in your group. Just knowing that you are "100%" isn't all that helpful, but knowing that you're close to losing hate is.

So yeah, I'd like something that shows the current enmity of all party members for your current target. If making add-ons isn't terribly difficult and the data is available I'll just do it myself.