bbellfish,
Well, I've been flying for almost 9 years and I still get the jitters occasionally. Like what was said above, I'd be concerned if you weren't. I get my jitters when I'm doing the maiden flight on a new plane, but other than that I'm OK the rest of the time. I'm an instructor at my field and I see new pilots getting this way all the time, so trust me it's absolutely normal. When you are doing your solo flight just act like you instructor is standing next to you as usual. You're definitely ready to solo or you instructor wouldn't be telling you you're ready. So just trust his confidence in you, take a deep breath, relax, and fly. Have fun!!!