Post by Ysera
Well, from experience, I leveled as a tank through the dungeon finder. I did a tank feral build I I found that some of the talents higher in the tree helped with aggro generation and damage reduction A LOT. Particularly as many of them came into effect around the Blackrock Depths phase.
Survival InstinctsFeral ChargePrimal FuryNatural ReactionWhenever I pulled too much, I'd use Survival Instincts. I used that spell a lot. Feral Charge helped me get to mobs faster, and let me start spamming swipe and maul quicker. Primal fury turned all of my agility, and thus crit, into rage which helped my aggro generation. Natural Reaction also helped with generating rage.
As you can see, I had a bit of trouble at lower levels with rage. So I took all of the tanking talents while leveling and they helped tremendously. Also, you can still do good damage in cat form with the tanking talents. While leveling up, you don't have to take the dps talents to do good damage. Most of the key dps talents are actually taken in a threat generation bear spec.
This might not have been the most efficient way to level, and it may have not been the best spec, but it is what I used, and I liked it.