It's obvious from the posts that no one is thinking of this in terms of the pvp aspect. The whole reason to add it's nice Mortal Strike debuff is strictly for pvp purposes and to tempt Hunters into using this shot more often then they currently do.
This will change things in the arenas greatly. More hunters will probably start out with these shots, and during the middle of the fights be using it more often then they currently do. As it stands the casting time kills us in arena. 3.5 seconds to cast 1 shot? Meanwhile we have a rogue, mage, warrior, etc. on us interrupting our shot, and usually by the time it does go off, the person has closed the gap on us, and we can't fire it off anyway.
Even Steady Shot has a hard time going off in the arena's, and as a hunter who actively pvp's, Arcane Shot, Multi-Shot, and Auto-Shot are your best bets. Steady shot is used only if no one is hitting you, and Aimed Shot is just out of the question unless you manage to find some one off in the corner and you're all by yourself with plenty of time to spare. Or you trap them, Scatter Shot, Wyvern Sting, Intimidation, etc. first. But still, Aimed shot is hardly used in the pvp world, and much like the pve world it's more of an opener shot then anything else.
Even with a 3 second cast, this won't prove to be very useful. Which is why they probably plan on toning it down even more after the patch goes live.
The cast time as well as the cooldown negate our normal DPS, and unless it crits you're obviously going to lose DPS unless it's used as strictly an opener shot.
