Saw this on the official forums and thought i'd share since this goes along with the LFR loot thread. All you have to do is simply make a macro(if you want, but it makes it easier) with the following line:
Now run this macro when your queue pops you should get a couple lines back in your chat box, what you want to look for is the the last few lines. They will show something like this:
 indicates the number of bosses killed so if it says = 0 that means it's a fresh run. Hope this helps some people.