No, you can find a use for dual-wielding double swords. Oh, I don't know-maybe taking on multiple enemies at the same time? That is, provided you and/or the NPCs can have cool swordfighting animations and the AI to go with it(Bungie did try this with the Elites, but it didn't made it). Well, you is pretty much out of the question since Halo isn't a fighting game. Besides, swordfighting in video games haven't even been perfected yet. You'd have to probably go virtual reality.
The NPCs will look cool and be useful doing it, if they can take on several at a time-but you won't and can't.