If you are going to have a descent/ascent rope you could tie your camera to it on your way up and just pick it up when pull it out...
I guess if you're going to hook a wreck, or anchor over a spot for one dive and then disconnect prior to ascent, this could be an option. However:
- many wrecks have semi-permanent mooring buoys and ascent lines on them that aren't pulled up....so this isn't an option......which leads us to......
- mooring/anchor lines break........often.......and in random spots. Now we're back to a search and recovery dive the next day 
- mooring/anchor lines bounce, even in relatively calm seas. The camera, tether and clip could be subjected to some serious jarring. Every now and then we leave a contingency bottle of O2 or 50% on the line if the boat doesn't have a hookah line. Twice, it wasn't there when we returned. Back to a search and recovery. 
With a scooter and a reel you can cover a lot of ground in a search (that's how we found the deco bottles), but its a waste of a dive (and helium) at 200+ feet. I love scootering as much as the next guy, but mud and silt gets monotonous after a while.
No thanks.
The camera gear costs too much to abandon to the whims of mother nature and rope manufacturers. If there's an emergency and I have to abandon the camera, that's a choice I'm ready and willing to make. I just don't want to have that choice made for me through pure chance.
In the end, as with any change in equipment configuration, invest some shallow dive time practicing with the doubles, stages and camera. It should become a very natural part of your routine. I plan to try some ambient light tripod shots on some wrecks between 180ft and 250 ft this summer. You can bet that I'm going to spend several weekends in April/May freezing my butt off at 30 feet in a quarry practicing with this new and unfamiliar piece of gear that I would like to take deeper. I anticipate taking lots of photos of abandoned mining equipment before I'm comfortable 
Stefan