I published my first app in the iPhone App Store a little while back, here are a few loose thoughts on the matter:
Approval process takes too long. It took a week to get initially approved for my app and an update I put in for took about the same. It's a very discouraging process to have to go through. It'd really be nice if the initial approval took a week and you get a pass on updates. I know that opens them up for abuse, but couldn't I just sign one of those 'on my honor'...