So I headed up to the Aldor Rise in Shattrath to test it out, and sure enough, even with the latest buffs to Bombardment, it comes no where near close to making using Multi-Shots do as much damage as Aimed Shot (with Lone Wolf).
Let's take a look at the numbers. I'm using a 660 weapon (952-1430 damage) on the Beta, but since all the shots we'll be looking at are based on Weapon Damage, various gear shouldn't change how these shots compare relative to each other.
|Multi-shot:||40%||*||Weapon Dmg.||*||# of Targets||*||C, V, M, Ms, PhV, Arm|
|Aimed Shot:||420%||*||Weapon Dmg.||*||Lone Wolf||*||C, V, M, Ms, PhV, Arm|
If we really wanted to know how much damage these shots were doing averaging, we'd also have to add crit, versatility, mastery, multistrike, physical vulnerability and armor multipliers, which in my case, all works out to around a 17% buff, but since that'll be the same for both of these, I'll ignore it for now.
With an average weapon damage of 1191 and AP of 4850, that puts Multi-shot at about 2399 damage per target (without bombardment), or around 3838 with bombardment. For Aimed Shot with lone wolf, however, we're about 32,750 damage, or 47,624 damage during Careful Aim.
Now, even if we imagined that you could keep up Bombardment 100%, while also using Chim Shot and Barrage on CD (maybe I'll get into those numbers in a different post, but having our signature shot double in damage when there are multiple targets is just awesome), Multi-shot would need to hit 13 or more targets to do more damage than an Aimed Shot. If we consider that Aimed Shot takes about 2.19 seconds to cast, we could consider we can cast that many Multi-shots, but we'd still need 6 or more targets to make 2.19 Multi-shots do more damage than an Aimed Shot (and we'd have spent a little bit more focus in the process).
So what we're left with is using a single target rotation, and relying on barrage and Chim Shot to give you a burst in cleave damage. This actually isn't a real problem, because generally, in raid AoE situations, there's still a priority target, and being able to focus all of your normal single-target rotation damage into your focused target will be beneficial to the raid. If there are any situations with enough adds alive long enough that could possibly warrant using Multi-shot as MM, you'll probably want to switch to BM for that fight, anyway.