Thanks Tzenes for the thread, weapon speed is indeed an important aspect when considering weapon upgrades. What I'll try to do here is combine Methods numbers for different stats coef with average base damage of end game weapons to sketch an approximate list of 2 handers (from best to poorest) for dps dks. Obviously, getting the exact result (exact value of each weapon translated in AP) requires a perfect model for dpsDK which does not exist at the moment (while people of Rawr are working on it). My point is that it may be possible to get the EXACT list for 2h weapons without having an exact model for dpsDk.
First of all, here is the list according to loot rank and using Methods numbers (after hit cap, before exp cap, without ghoul considerations) : (abd = average base damage)
1. Betrayer of humanity 222.9dps- 758abd - 1811.788
2. Inevitable Defeat - 203.7dps - 692.5abd - 1770.244
3. Jawbone 203.6dps- 733abd - 1724.662
4. Death's Bite 203.7- 692.5 - 1686.456
5. Armageddon 203.7- 692.5 - 1657.024
6. Cryptfiend's Bite 203.6dps- 733abd - 1633.932
7. Black Ice 203.7- 713abd - 1610.696
I'll now find a lower bound for dps increase due to an average damage increase x. I'll do it for the unholy spec 17/0/54 , it should then be a lower bound for all dk specs since it was often stated that the unholy spec is the less dependent on base weapon damage. To find this lower bound, let me consider the usual rotation
PS > IT > SS > BS > BS > RP dump
SS > SS > SS (with RP dump when necessary)
over 18 sec. I'm then obviously forgetting about SS glyph. Let me also forget about ALL talents/presence/T7/etc and even consider that none of our attacks can CRIT (I'm forgetting about any damage boost in fact). You may think I'm putting too much aside, but wait to see the result before yelling at me

.
Here is then a 1st approximation to the formula accounting for our dps increase due to an average base damage x_{1,2} for weapons {1,2} :
dps_increase = x_2 * (#_White_Swings+PS_percentage+4*SS_percentage+2*BS_percentage)/18
-x_1 * (#_White_Swings+PS_percentage+4*SS_percentage+2*BS_percentage)/18
[top] x_2/Weapon_speed_2 - x_1/Weapon_speed_1 + (x_2-x_1)*(4.7/18).
If you go back to the list above you'll see that abd_difference
20.5 or 40.5 if you seek the abd difference between 3.4,3.5 and 3.6 weapon speeds for all the 203dps weapons of the game. This result in the lower bounds for dps increase
dps_increase = 5.39 from 3.4 to 3.5 weapon speed
14.43 from 3.4 to 3.6 weapon speed
33.75 from 3.4 to Betrayer of humanity.
In other words, if I am not mistaken, those are the minimal dps increase you'll get for any dps dk spec using a two hander. Now, to adjust our weapon list with this knowledge, I'll use Methods ratio 1 dps = 6.32AP to put
+34.06 to 3.5 weapon speed weapons
+91.20 to 3.6 weapon speed weapons in the list
+213.3 to betrayer of humanity.
The new list is :
1. Betrayer of humanity 222.9dps- 758abd - 2025.09
2. Jawbone 203.6dps- 733abd - 1815.86
3. Inevitable Defeat - 203.7dps - 692.5abd - 1770.244
4. Cryptfiend's Bite 203.6dps- 733abd - 1725.13
5. Death's Bite 203.7- 692.5 - 1686.456
6. Armageddon 203.7- 692.5 - 1657.024
7. Black Ice 203.7- 713abd - 1645.03.
I found those results already quite shocking. Note also that since my numbers should be a lower bound on the dps increase, it would mean that with the true values, the slower weapons would still go up in the list.
Noticeable changes from new list :
1. Jawbone goes second by a fair margin (which would grow with the true values)
2. Cryptfiend's Bite goes over Death's Bite.
Another note, any dwarf/human/orc not exp cap should adjust the values consequently. For example, Death's Bite and Inevitable Defeat are almost on the same lvl for an orc not exp cap.
Oh, and last remark, I think that if we had the crit chance/talents/all damage modifiers in the calulus the dps_increases I have stated would still go up by about 50% (something like this I think).
I would be happy to get feedbacks on this. I feel this list is different than everything I saw before and different from what Rawr is suggesting also. I hope nothing is wrong and that it will help people choose between weapons.
N.B. : Just realized I used Methods numbers for the unholy spec, did not check what exactly would be the difference if I had took other spec values.