And it also depends on what you're doing in-game, PVP or PVE. I'd probably go with Fury, just because I <3 the style of a dual-wielding fury warrior.

I can't see dual-boxing warrior/priest in pvp being overly effective. It definitely looks good on paper, but warriors aren't great at protecting their mates and they are just too micro intensive. While solo playing a healer I stopped following warriors around a long time ago and went with rogues. Rogues could keep me alive so much better with their CC/stuns whereas a warrior couldn't keep me alive at all once he used his fear. I wouldn't suggesting using Rogue/priest combo either, simply because healing/dps'ing by using multiple classes is really hard. It's difficult enough to use one class (shamans) to do both.

In PVE it's a cakewalk though. And to get back to your question, Fury is looked at as the PVE dps spec.