I brightened the image in ACR, then opened the image in PS as a smart object.
Duplicated the image and changed the duplicate to a regular layer.
Went back to ACR with the bottom layer and reset the dark original.
Changed the duplicate layer to screen mode and masked to only reveal the brighter bride and groom.

forum discussion: http://forums.dpreview.com/forums/read.asp?forum=1006&message=29016664

original image by Dave Patterson: http://midwestshutterbug.com/gallery/test/IMG_3748_1