On a scale of 1-10, the feral's DPS in the first 4 seconds of a fight is a 9. Very few classes can put out the burst as consistently as they can (mostly because of their 30% crit). Not only that, but during that burst, your target is stunned. In 4 seconds, if both of your shreds are crits, you'll put out about 1.1k-1.4k damage (depending on target's armor). After those first 4 seconds, a feral druids DPS is probably around a prot paladins...I'd rate it a 1, maybe a 1.5.
The key is to switch your rolls to maximize your potential. After those first 4 seconds (and maybe a faerie fire), you can switch to bear to either interrupt a spell cast, bash a target for extra control, or tank until you get a nature's grasp on the target. go travel/caster in order to throw around a heal to a teammate or root an opponent. OR, you can cheetah form to restealth. The situation dictates the best move. The strength of the class is that you do have all of those options.
Once you've made the most of the following 6-8 seconds, you can go back to cat form with 100 energy, shred, shred, FB--and have the potential for another 1.5k damage in a 5 second time frame.