I think Firelands sounds great, one of my favorite parts is there only being 7 bosses. 12 just felt overwhelming to me. Not everyone playing this game has the time or dedication to spend the time it takes to progress through 12 bosses. With my guild we were so time limited due to peoples jobs and personal lives that by the time we got up to a progression boss, our time was out from killing a ton of bosses before it which slowed our progression down a bit.
If 7 bosses isn't enough for you because you have that much time to dedicate to the game where you'd want more, great, good for you, but keep in mind not everyone does. Go get an alt to raid on to kill time, or do hard modes, I'm sure they'll be much more time consuming.
On top of dailies, the daily not so random heroic, and farming for raid mats I find it hard to see how people can still whine that they want more, go outside, the world's a beautiful place.
Please, don't ruin this by complaining about it.