Should DW warriors roll on daggers?

Seeing how DW warriors really benefit from fast weapons (given the right build and all), there's no real reason why they shouldn't.

Be sure you know what you do though. On one hand, there are skills for rogues that really require a dagger. They don't have any other option than using a dagger for these.

Warriors on the other hand have skills like unbrindled wrath, which really benefits from fast weapons - and since there are really few good fist weapons available, fast weapons pretty much equals daggers. Faster weapons also benefit more from skills like enrage and flurry than slower weapons, and quite a few daggers have +crit on them, which triggers flurry (and that in turn is a fury warrior's bread and butter, the one skill they really rely on almost all the time).

So, in the end, a rogue will most probably benefit a bit more from a good dagger than any warrior. But a DW warrior will benefit almost as much.

It's best to discuss this in your group and either agree with the rogues or let the group leader decide.

By the way, you might want to bring this up on your realm forums, since many rogues regard daggers as "rogue only weapons" and will call you a ninja for rolling on them. I did bring it up, have a look if you want.
http://arathor.net/showthread.php?t=2565