Kill Shot will be on the global cooldown (GCD) when 3.1 lands This means a few things. Most notably, it means that it will no longer fit magically into a macro. Secondly, it means you'll need a space for it on your bar and need to get used to using it. Kill Shot is always the best shot you can make if it's up.
I bring up the following for two reasons. First, some people don't know this, including a few at EJ. Secondly, I had a previous post detailing that you should make all your main shots macros, and include the magical Kill Shot in there for maximum Kill Shots per target. Those will no longer work.
This service announcement brought to you by the emote: /sigh.