Wish we had dedicated threads for each of the specs but anyways, this is my observation from a very limited 5 minutes of testing with each type of weapon. As you all know DW numbers won't be as big but I was using the 620 pvp 2H and comparing numbers to 2 620 pvp 1H weapons. The 2H obli was critting for roughly 570k on average (on a level 85 dummy) with my gear and frost strike crits were around 200k on average. On the other hand using the DW set up, obli was critting for around 160k and frost strike was critting for around 125k.
So while yes, you get more killing machine procs you're still limited to runic power production that is reliant on your runes and they are recharging at the same rate regardless of weapon. If each weapon swing gave you like 10 runic power I can see how weapon choice doesn't matter and it evens out, but as how it is, could somebody explain to me why DW would ever be viable if you're trying to get the highest dps?