I’ve done some math earlier today regarding this issue. 33/28 (blood frenzy in arms, not second wind) have improved slam, 3/5 flurry and weapon mastery while 41/17/3 provides Improved MS and ER. With 33/28 you do damage cycles like this:

Swing, Slam, MS | Swing, Slam, WW | Swing, Slam, MS | Swing, Slam | Swing, Slam, MS (WW is ready at this point, but can’t be used due to GCD conflict) | Swing, Slam, WW…

For the sake of simplicity, let’s assume that with 3.6s weapon and 3/5 Flurry your swings are done at the speed of 3.1s, when you add Slam to that swing, with perfect timing and 0 latency (never in reality) you will swing at the speed of 3.6, which is same speed as without Flurry. Because you have to time abilities between Slams and white hits, you are not using them every time they are ready, but rather every 2 swings = 7.2s for MS and every 4 swings = 14.4s for WW. With 41/17/3 you don’t have such problems with timing, you are using MS every 5 seconds and WW every 10 seconds, no GCD conflicts either. Here is the math done on those assumptions:

2000ap
130 weapon dps
3.6 speed

White dps: 272.8

MS damage: 471 + 468 + 210 = 1149

33/28 MS dps: 1149 / 7.2 = 159.6
41/17 MS dps: (1149 / 5) * 1.05 = 241.1

WW damage: 471 + 468 = 938

33/28 WW dps: 938 / 14.4 = 65.2
41/17 WW dps: 938 / 10 = 93.8

Slam dps: 272.8 + 140 / 3.6 = 311.7

Total 41/17 dps: 272.8 + 241.1 + 93.8 = 607.7
Total 33/28 dps: 272.8 + 159.6 + 65.2 + 311.7 = 809.3

And so 33/28 can produce up to 25% more dps then 41/17. That “up to” is the key here. First, using Slam every swing is huge rage eating. How much rage can you generate per swing? 20? 30? Sure you can Slam every swing, but you need to produce rage for using MS and WW as well. 41/17 will produce much more rage then 33/28 in this scheme of things. Also, this is assuming perfect reflexes and 0 latency, Now let’s do same thing assuming being 0.5 sec late with Slam, in this case your Flurried swings go up to 4.1second:

2000ap
130 weapon dps
3.6 speed

33/28 White dps: 272.8 * 3.6 / 4.1 = 239.5

MS damage: 471 + 468 + 210 = 1149

33/28 MS dps: 1149 / 8.2 = 140.1
41/17 MS dps: (1149 / 5) * 1.05 = 241.1

WW damage: 471 + 468 = 938

33/28 WW dps: 938 / 16.4 = 57.2
41/17 WW dps: 938 / 10 = 93.8

Slam dps: 239.5 + 140 / 4.1 = 237.6

Total 41/17 dps: 272.8 + 241.1 + 93.8 = 607.7
Total 33/28 dps: 239.5 + 140.1 + 57.2 + 237.6 = 674.4

Something as simple as being 0.5s too slow with Slam every swing is lowering your ideal dps with 33/28 by ~17%, slower swings means slower Slam and slower MS/WW cycles. Now god forbid you will have any rage issues with white hit every 4.1 second, comparing to 125% rage giving swings every 3.6 with 41/17. In normal instances and heroics I’m pretty sure 41/17 can easily compete if not beat 33/28 for dps, raidbuffed however the rage issues of 33/28 can be gone (windfury totem and whatever can you get), which allows you to use all your abilities to it’s fullest. Theorycrafting is fun, but we will have to wait a bit and see how it really works out in game, people will get right conclusions after few days.

edit: Oh, yes, you should also add ~2% more dps form WM to 33/28, which I haven’t done here.

Terhix