I was dreaming up a build while at work, man I wish we had a calculator for RoS, or at LEAST an updated legendary item list! (hint hint dfans!!! lemme in beta and I'll make one myself =P )
I really want to try;
Strafe w/ rocket storm (strafe does 315% now, and the homing rockets do 90%), and the zero cost legendary.
Fan of Knives w/ Knives Expert (the rune removes the cooldown and adds a 30H cost, and FoK does 450% in 20 yards)
Smoke Screen w/ healing vapors (SS breaks CC and grants immunity for 1 second, the rune adds a 15% life gain per sec)
Companion w/ Wolf companion (the wolf does 150% weapon dmg now), and the 3 wolfs legendary (pretty sure it's a cloak)
Chakram w/ Shuriken Cloud (constant 200% weapon damage aoe)
Vengeance w/ Stimulants (rune heals 6% life per second, and vengeance lasts 15s and is just an insane DPS cooldown)
Bloody Vengeance (globes grant 40H and 4D)
Hot Pursuit (grants 20% speed when you hit an enemy)
Ballistics (100% additional rocket dmg, and 20% chance to fire a homing rocket for 150% dmg)
Single Out (+20% crit chance against targets that are not within 20 yards of other targets)
The idea here is with free strafe, you move around doing constant damage with both strafe and shuriken cloud. while dumping your hatred with a ton of FoK's that have no cooldown. After watching a couple streams strafe actually hits hard enough to be viable. Hot pursuit which is changed to increase your movespeed by 20% when you hit a target hopefully works with strafe, because that would be pretty sweet to almost completely offset the decrease in speed while using strafe. Bloody vengeance ( 40 hatred and 4 disc per globe ) is there because it's just extremely helpful to get a nice chunk of your resource back.
You get some rocket synergy from your passive and strafe. Since strafe lets you move through enemies vault isn't really needed, and my big defensive skill is smoke screen to pop if I'm about to get frozen, and while 15% of your life when you pop it isn't 'huge', it's still pretty damn helpful when you use it twice or so to heal back up.
Vengeance with stimulants (which grants 6% life each second) is there for the DPS as well as another healing cooldown.
One weakness I foresee with this build? It has lower single target than other DH builds. Once you've got 1 elite / champ / boss left then obviously there's better nukes for the DH. I try to offset this however with a couple things; Companion w/ the 3 wolf legendary (450% combined damage from them per attack), rocket storm and ballistics which since they home in, should work well against 1 target, and of course the awesome Single Out passive, which grants 20% crit chance to any targets that are not within 20 yards of other enemies.