So, this was never answered, but just in case anyone is looking for a possible fix, I figured it out for me, at least.
I can't count how many times I ripped out iTunes, Quicktime, Apple Mobile Support, Apple Installation, Bonjour, and whatever the 6th one is I'm forgetting. Anywho, after reinstalling iTunes over and over, my iPhone, nor my old iPod touch just wouldn't show up. Finally I took my mom's iPod nano 3g and plugged it in, and voila, there it is under Devices. Needless to say, I was very pissed because I figured that meant something was wrong with my mobile devices. But after ejecting the nano, I plugged my iPhone right back in, and boom, there iTunes asked me if I wanted to upgrade to 4.0. So I dunno if it just needed something familiar to jumpstart it or what have you, but there you go.