Hehehe. Dealers are typically the very last to know about new products. Most Nikon sales reps only "know" rumours until they are called in for a sales meeting prior to introduction. NDAs go to major media like Pop Photo or DPReview, not little Podunk camera stores with big-mouthed employees who pre-announce stuff they don't have a clue about. It's entirely possible that huge retailers such as B&H get some orientation prior to announcement, but they are not going to blab. I do know dealers who were taking pre-orders on the Nikon D800 and D400 for almost a year each -- anything to get you visiting the store regularly.
I signed a few NDAs before I discovered they were too limiting and more trouble than they were worth. No one will risk their NDA status by announcing anything. Back in the dark ages, I once got in trouble with Microsoft for even hinting I was under non-disclosure (all I actually did was use a secret code name for a product.) Another vendor called me up because some idiot happened to spot an unreleased product in my office, and then called the vendor to ask for one because he was a hot-shot developer. Geoff from Nikon once called me because one my futuristic blog posts wasn't clear that it was just speculation on my part, and my predication was uncannily, but only coincidentally spot-on, and he wanted to make sure there wasn't a leak. I made sure I added a few IMHOs in the future.
All in all, your camera dealer is your second-worst source of information about upcoming products, behind only the "guy who knows somebody who knows somebody who works in the factory." Pros working under NDAs won't tell you. Sometimes folks in the factories do leak stuff, but it quickly turns up on NikonRumours.com. Speculation is a heck of a lot of fun, but not something to base buying decisions on.