While the agility weapons provide more avoidance through dodge, the strength weapons tend to have more of a stat budget allocated to stamina. With Aesir's Edge for example, you get a lot more stamina out of that than you do from the Stormrune Edge, when they are the same ilevel. Strength would also provide more TPS than an equivilent amount of agility, while also providing a little bit of avoidance through parry.
In short, you generally get more EH and TPS from strength weapons than agility weapons, while agility weapons win for avoidance. It comes down to personal preference in the end.
100+ agility is a nice boost to avoidance. But you should also consider that avoidance is subject to Diminishing Returns, and Strength/stamina are not. strength also passively increases DK avoidance by a small amount as well (100 strength = 25 parry rating), whereas the AP that is on most +agi 2h weapons has no effect on your parry rating.
this doesn't mean using a +agi weapon is bad; but I think Edgewalker is right that the advantage leans toward +Str 2h'ers in this case.
If it helps, I have done some simulations and analysis of the threat equivalency points of each stat. So expertise is our #1 threat stat up to 6.5% expertise, then hit or strength next, depends on your tree.
Agility is for avoidance, which in fact makes it very desirable for tanking weapons though, but for its avoidance as opposed to threat. AGI for threat is very weak (around half as good as strength per point).
You need to use judgement to decide if you should go for an agi weapon or not.
If you want the detailed numbers (ie. blood, unholy and frost EPs), they're are in this article.