A little more info on my spec. Did all of TK up to Kael (new people learning the fight ftl). We have a new Rogue who outgears me, using Combat Swords. He's pretty good, so he'll be a good benchmark of Combat Swords versus Hemo.
Al'ar
Me: 755 DPS
Him: 674 DPS
VR
Me: 921 DPS
Him: 995 DPS
Solarian
Me: 1110 DPS
Him: 1131 DPS
Full Raid (Including trash)
Me: 866
Him: 846
So, it's pretty close. He beat me on VR largely because VR is bleed immune, and he has Improved Eviscerate, while I don't. Al'ar I can chalk up to him being relatively new to the fight, and probably being a bit conservative on DPS. Solarian is neck and neck, with only a 21 DPS difference. I don't know if he popped Blade Flurry for the adds (which I do not, I take unnecessary damage that way).
The Kael attempts varied widely. I ranged from ~900 DPS to ~1100. His DPS was skewed because he was using ranged attacks in Phase 1 (I'm lazy, and it does not help the raid in any way for me to shoot the adds).
So, I'd have to say that Hemo and Combat Swords are roughly equal in terms of damage. The raid buff Hemo gives is likely to push it a bit over Combat Swords for total raid damage, but that's hard to say from just looking at DPS numbers.
Can't wait to get into Hyjal so I can use Rage Winterchill as my benchmark fight.