01gt4.6, I find that this study does nothing more than demonstrate the obvious by doing a very weak experiment.
A carb only sports drink contains zero grams of protein (obvious). Chocolate milk contains several grams of protein (also obvious). Protein is required for protein synthesis (obvious). The study essentially shows us that consuming protein increases protein synthesis. WHO WOULD HAVE THOUGHT?!?!
The second thing the study found was that the chocolate milk promoted more glycogen stores than the sports drink. One would expect a sports drink that featured only carbs would have been designed exactly for this purpose, and perhaps also expect a drink which has lactose as the sugar would fall miles behind the sports drink. But we must not overlook the protein factor. It is understood now that a balance of carbohydrates AND proteins taken after workout promotes the highest insulin response and therefore replenishment of glycogen stores. This is why post workout shakes and those kind of things (not "sports drinks") contain a mix of carbs and proteins.
So, quite obviously, chocolate milk is vastly superior to a sports drink during the post workout. A "sports drink" featuring only carbs is almost certainly meant to be consumed DURING activity to keep you from tiring out. If anyone uses something like that for recovery, they are a fool.
A more interesting study would be to pit chocolate milk against a real post workout shake. I'm talking something that features whey isolates as the protein source and dextrose/maltodextrin as the carb source AND is formulated to have a specific balance of each. I think the winner here would be as obvious as in the study you're talking about, 01gt4.6.
In my opinion, if you are looking for optimum results, chocolate milk is not the best choice. But if you are looking for easy/better tasting and can deal with weaker results, then by all means go for it. It (obviously) beats drinking a red bull or whatever.