I don't think there's anything in Islam that forbids this? If the photos are taken with the consent of the people, then what's wrong with that.
It would be a little hard to ban every one in a wedding taking pictures.
EDIT: On a quick google search, I found this:
http://www.islam-qa.com/en/ref/10668
I think the main reasoning behind this is that people start to respect the people in the pictures etc. So, in terms of just capturing the moment of of the bride and groom only, then I guess it would be alright. :confused: