In a raid environment mages are stacking pretty well now once the gear gets up to par. In five mans I sometimes have a hard time keeping up but its not a problem on raid bosses. Right now almost everyone in our guild is in the 4000-4500 range on tank and spanks with the hunters being around 5000. The key to the high dps with frostfire specs is high crit, with a lot of back to back crits for hot streaks. With crit being the key there are going to be good and bad nights and rng comes into play a lot more but overall our dps is looking much better right now in comparison to others than it was in BC.
We run 2 mages and I personally didnt have my greatest week, finished 10th on patchwerx but with 4181.
http://wowwebstats.com/dnpbg6wgdhn23?s=242012-275295
We also finished 2/3 on Archivon with both over 4000, which is another pretty much tank and spank.
(My mage is Malanir, until the name change cd comes back up so i can switch back)=)