I think the problem with that is that Marston's original vision of "Diana Messenger of Peace" thing still holds true.
Whereas the lasso is less violent looking, the unspoken connection people make with say an arrow is something lethal. I think Green Arrow pretty much exhausts the non-lethal imaginary uses of projectile weapons as it is. Boxing glove arrow, anyone?
People had the same problem with the "ultimate wonder woman". Remember she had a glowing gold axe instead of a lasso? She could slice and hack objects and obstructions, sure. But the natural assumption is that sooner or later, she'd be hacking at *people*.
I have a feeling I'm opening up a can of worms here, so I'll stop. But not before saying that I don't think Diana needs weapons at all.