Yup, you need two targets.Targets: Two creatures within 3 squares of each other
Yup, you need two targets.
If you want to use it on one creature... just use Twin Strike. It's 90% the same thing.
uh, two rolls to hit, take best one and do 2d10+dex vs make two attacks doing 1d10 each? I don't think so!
Hongs solution is the sensible one. You use the mechanics as written, and one arrow hits the target and the other arrow is wasted. You still get to roll twice and do 2[W]+dex damage though.
I don't have a problem with using this with a single target. You shoot the ground or something.
(No, you don't get to do all your shots on the one guy.)
Choosing Targets PHB page 272:
When you use a melee attack or a ranged attack, you can target a square instead of an enemy.