Originally Posted by
Mammoth
All unit frames will have enemy cast bar, including default. If you can only look at a small part of the screen, move the boss frame near your actionbars. From what I've seen this is a common setup.
Other addons: Icehud will do cast bars around your character for yourself and the target.
Imo, we were always good at interrupting, this new talent is just encouragement for people who were too concerned about personal dps to interrupt before now. And since the majority of boss tactics requires you to know what the boss is doing, I'm surprised you don't already monitor the cast bar.