Well, I am not 100% positive on this, but I was just trying to figure out if daggers attack at the same speed as swords using the pre-order daggers on my IW mesmer. Well, It turns out that sometimes I get a double attack! I don't have a stop-watch so I can't tell for sure about the attack speed, but it does feel faster... Anyway, I definetly get double attacks every 10 or so attacks it seems.
I notice that the daggers have Dagger Mastery +1 (20% chance while using skills) but this should not fire while attacking, should it? Even if it did, according to the statistics of the whole thing, I should never get a double attack... Let's see...
20% chance to have a 2% chance for a double attack. Would that work out like... 2 * 0.2 = 0.4% chance to get a double attack?
This is absurd, that's my conclusion.