Huh, I guess the PR folks are already all over this one. Makes sense, Nuun's got a crack team of social media czars running the operation. Can't let these message board rats hurt their sales.
Here's the real skinny: Electrolytes are pointless for marathoners. Your normal diet already has plenty of sodium in it, and the other elements you lose in sweat are negligible. Unless you find yourself with a massively overpowering salt craving, you are not electrolyte deficient. All electrolye drinks are relying on slick marketing and patently false claims to sell their products. As Tim Noakes wrote, "The ingestion of sodium chloride during exercise appears to be without any biological advantage." There are no scientific studies that demonstrate an advantage of electrolytes over no electrolytes. Yes, there's an advantage of sports drinks over water in some situations (like high-level marathoning), but it's because of the sugar alone.
For the general population, and for typical training, water is the only beverage you will ever need. Sugary drinks are in fact unhealthy if you are not currently (at this very moment) engaged in high-intensity, long-duration exercise. The only -- THE ONLY -- benefit of a sports drink like Gatorade over water is the fact that it contains an optimal amount of sugar to replenish your glycogen stores during your race. One of the reasons why HFCS is bad for you generally (rapid absorption through parallel pathways in the stomach; different metabolic pathways in the body) is also why it's great for marathoning. There's a wealth of scientific research that shows that ingesting carbohydrates, especially a glucose + fructose blend, during long, continuous runs at high speeds improves performance. Since sugar is what Nuun does not have, it's silly and pointless to use it for exercise. No other sports drink ingredient has a lick of evidence supporting its use for performance or health. Well, except for the water I guess.
Even a traditional sports drink is only necessary (for performance at least) during races of 45min or longer, and in HM/marathon-specific workouts. Until you get to 90min+ duration races, you don't even need to swallow it, just a swish and a spit will do if you like. Even a 22mi easy run does not even come close to depleting your glycogen stores if you're built like a typical distance runner, since easy to moderate running relies more heavily on fat for metabolic energy. This is also why Joe Jogger won't even miss the Gatorade at Cal International - recreational runners do not run at a very high fraction of VO2 max, so they don't rely on carbohydrates for as much of their energy. Do note that, for the sake of race-readiness, it does make sense to practice drinking during some of your long runs, though.
Shoutout to the PR control crew at Nuun, you're doing a heck of a job trying to control the message! Sorry to burst your bubble though. Maybe shipping free Nuun to more athletes and making them post on twitter about it might help.
All in all, pretty dumb decision. I hope that Cal International at least lets the elites going for OTQs bring their own bottles, otherwise you can kiss your chances of sub-2:18 goodbye. Well, unless you lug some GU along. Maybe the local running stores are in on the conspiracy, hoping to make a killing by jacking up the price of "race-ready shorts"!