The substantive change is partly because of changing desires of newlyweds, as well as the speedily changing technologies which can bring about an increased range of freedom for the photographers taking pictures. Gone are the times of film photographic equipment (to a large extent - sure, there are a few photographers using film cameras, but they are almost nonexistent at this point). Enter digital imaging devices, where the only cost of snapping an additional shot is the extra use of the shutter action, and the potential benefit is substantial. Now photographers can shoot for the chance of a wonderful shot, and not only when the great image is clear and present in the situation.
Most would claim that there are dual main methods of wedding photography at the present time - though seemingly all photographers find themselves utilizing both, sampling from the pair. They are:
1. Photojournalistic - This approach is emphasized when the photographer takes it upon herself to document the wedding, rather than pose participants of the wedding. It is 'journalistic' because it is an attempt to tell a story of the day, and not create an artificial and static look at the staged and posed shots.
2. Traditional - This outlook is most notable when the photographer arranges those people present in carefully thought out poses, very often gazing directly at the photographic equipment. Candid pictures are minimized, and activities are directed to ensure adequate photos.
It is an uncommon photographer, of course, that holds tight exclusively in one outlook, never straying or being lured in by the benefits of the 'other' style. Most common is the intricate blending of the two approachs, with an emphasis on one over another. These wedding photographers portray a great example of this blending.
Today's brides, and contemporary photographers alike, have almost entirely transitioned to photojournalists to capture pictures of the ceremony and reception that will have incredible meaning for many years to come. These are photos that would not be captured by a photographer who uses only a traditional outlook. You can find the top photographers here: Photographers Wedding.
Today's newlyweds usually agree on the real benefit of some posed portraiture - typically just before or just after the wedding itself - to capture the loving couple on their meaningful day.
For example, a popular present day method is to capture a wide variety of candid pictures throughout a wedding, and when posed shots are called for - often of just the loving pair or the entire bridal party - a 'fashion' portrait style is used to create dramatic posed, and so somewhat traditional, photographs, of the type that you might find in widely read fashion magazines. Though some claim this approach is something different than the two style mentioned, it is most easily described as a blend of the two.
See also this article on finding a wedding photographer.