Okay, I'm going to agree with sIKE on this one. I'm chocking myself up to a total brain-fart on this issue. It basically breaks down to targeting options vs actual targets. It is obvious that there are other creatures available, such as yourself, that you could target, but if you don't select them, then they aren't actual targets. Therefore, the line in the sweeping definition about no different valid targets existing would apply, since you didn't create any other valid targets out of the options presented to you.
I will point out to sIKE that on page 22 of the rulebook though, it does say a target is required for an attack. You can't just attack nothing. This is what I was getting hung up on, but since we are okay with the second attack not occurring I now realize it is somewhat irrelevant.
Sweeping says you must make the second attack if you have a target. Attacking says that all attacks must have targets. Therefore, I was thinking you'd be forced to select a target and carry through with the attack, but that is faulty logic on my part. I apologize.