I notice hunters topping damage charts all time. When I was grinding AB in the 30-39 bracket I noticed that the majority of the time hunters and warlocks were topping the damage charts.
That's PvP, not PvE. Of course ranged people will out-damage melee in PvP. There's no aggro.
It's not impossible for a hunter to top the damage charts in a PvE raid (ie: BWL, Naxx), but it's definitely much more difficult if the other classes are trying. It probably becomes impossible when the other members are trying really hard too. I'm not bashing on hunter damage, but that's pretty much how it is.