I am.
First tri too. I'm doing the Sprint distance this Sunday (.75k swim /22k bike /5k run)

I'm pretty pumped up too,and I've been training pretty hard for it. I've read all the horror stories about getting kicked around in the swim (literally) and one of my co-workers was just telling me that someone freaked out during her swim last year and grabbed on to her. I also have been told to expect a long run from the water to T1, on concrete no less.

The only OW swimming I've done is enough to try out my wetsuit a few times at the beach, but I know that it's mostly mental so I'm trying to psyche myself up. I'm a pretty strong pool swimmer, so I know I have the physical ability to get through it, I'm just hoping to hang back a little and avoid major carnage at the start. I figure even if I gas myself on the swim, I can recover a little on the bike and then hopefully have enough left for the run.

So, any Chicago tri veterans have any last minute tips you want to share?