Don't feel bad about checking and updating your wedding registry online -- there are practical reasons to do so. For starters, sometimes it's the only way to find out that your flatware has been discontinued. And if your highly preferred gifts are gone, you can add alternatives for the stuff you aren't quite excited about.
The downside? You'll know what you're getting in advance (quite a drawback for me, since I'm pathological about not knowing about presents).
How about you -- are you peeking? And is that exciting, or do you worry it will destroy the anticipation like me?