It depends on what you define as "pro"? Of the three people I personally know, one uses manual and the other two automatic. The person using manual also sets fstops and the like manually and uses a light meter.

It depends on the camera. One of the persons I know uses a Nikon (don't know the model) and looking at their photo's that they posed on the web for the bride and groom to order from they had many out of focus shots (I wouldn't even post them!). The other person uses a Canon 10D and from what I've seen they are all in focus. Both use automatic.

My Canon 20D we've shot multiple test shots at the past few weddings, the last one over 200 pictures, only a couple were out of focus using automatic settings and that was because it focus on the wrong object, you have to watch the focus points. It does a better job focusing that I ever could looking through the viewfinder and besides often there isn't time to focus.

I've heard of some higher end cameras which track your eye movement in the view finder to determine what you want the camera to focus on!

With the canon lenses I've been getting the ones with the image stabalizer in it to help also, why do something manually when an automatic process can do an equal or better job?

... Gary