[img]http://imageshack.us/photo/my-images/69/tableyk.jpg/[/img]
................dagger.......longsword..dmg ratio...snedagger..snesword..dmg ratio..overall ratio
iron...........5..............10.................0.500...........15..................6.................2.5.............1.250
fine iron.....6..............11.................0.545...........15..................6.................2.5.............1.364
steel.........7..............12.................0.583...........15..................6.................2.5.............1.458
fine steel...8..............13.................0.615...........15..................6.................2.5.............1.538
silver.........9..............14.................0.643...........15..................6.................2.5.............1.607
dwarven.....11............16.................0.688...........15..................6.................2.5.............1.719
elven.........13............18.................0.722...........15..................6.................2.5.............1.806
glass........15.............20.................0.750...........15.................6..................2.5.............1.875
ebony.......17.............22.................0.773...........15.................6..................2.5.............1.932
daedric.....19.............24.................0.792...........15..................6.................2.5..............1.979
As you can see, if the base weapon ratings for daggers are the same in Skyrim as they are in Oblivion, there isn't much difference in damage potential at first. But it starts getting higher the better the weapon and maxes out to about twice as much damage potentail for that first hit.
Plus, if you can get two single sneak dagger attacks in for one longsword attack, that is potentially ~4 as much damage {(19*15*2)/(24*6)=3.958}. I'm unsure how a single dual wielding attack would factor in. This is assuming just a single dagger vs a single longsword.
It was something I was pondering yesterday after I saw Sam's perk/race post. This should gives us assassins and thieves something to chew on for a bit.
PS If anyone has any good data on actual Skyrim weapon ratings, let me know. I'll add a SkyrimWR*SkyrimSneak damage table as well.
EDIT: Added a link to the table since the text isn't displaying well.
EDIT#2: Added in periods to make text table more legible.