What is your 5D + DPP + CS3/4 work flow?
Have you tried the Lightroom demo? This pretty much addresses your problem. I too have the 5D and use LR for almost all the PP work. You can make the adjustments to one of the shots in a batch of pictures and then apply the same edits to all just by copy/paste. Then you can print/export to web page right from with LR. I do very little editing in PS now.
FCAS Member #127