Hey, I've got at least one wedding photo (as we were about to leave in the car) that makes me look purely evil!
They also got one of me and my wife that makes her look drunk.

Its those fun photos that can sometimes make a wedding album. We look at those and laugh every time (even though it was just 7 months ago).

Editing the photos to make them all look better/perfect takes some of the real emotion from the day.

Your work looks good, but I would suggest that you really reconsider editing it like that.

Here, I got the funny one of me. I wouldn't edit this for the world. It is just great, whether it makes me look bad or not...
http://www.flickr.com/photos/yuns_avatar/2508742524/

The after pic looks great... the before pic isn't all that bad.

Also, there probably were people that took pics of them with there own camera's as the couple left the wedding.

well we'd have to see some pictures of her smiling that werent edited, to see if she looks normal....people who know her may find it really noticeable....personally i think her face looks kinda weird & crooked in the after pic and her nose and mouth look too big. i agree with the first answerer who suggested just leaving it as it was.

Find a better image. The original has her facing forward while the modified one has a face in semi-profile.
The colors don't match either. The original is warm and dull while the pasted image seems to be taken from an indoor photo with flash. The face shines too much. So yeah, if you don't have a better face to paste then dull the shine on the modified photo and change the tonal values. I haven't tried this but I think a short way to do it is to go back to the psd file (assuming you still have it and the images are still on separate layers) and change the layer mode of the pasted face to overlay or multiply. Try it and see if it works.
Third option would be to work with the original and just move the irises and distort the mouth a little to make her smile.