Print copies of the May issue of Motor Trend arrived in Michigan over the weekend. I quote:
"The rollout for the C7 Chevrolet Corvette will look like this: The standard coupe will launch in late 2013 or early '14, with the convertible coming three to six months later. The Z06 is next, a full year after the standard coupe. Then comes Gran (sic) Sport coupe and convertible, with the ZR1 the last of the next-gen Corvettes to hit showrooms. Rumor has it that the ZR1's supercharged 6.2-liter V-8 will shrink in displacement slightly, for corporate average fuel economy reasons, and there will be a 3.6-liter V-6 version of the base Corvette, though not at launch."
Now, keep in mind, this is Motor Trend's prediction. No attribution is given to any official statement from Chevrolet. At Motor Trend, the editors apparently don't even know to spell Grand with a "d." However, if correct, my translation of this the rollout would be:
Fourth Quarter 2013 / First Quarter 2014 - Base 2014 Corvette Coupe
Second Quarter 2014 - Base 2014 Corvette Convertible
2015 Model Year - Z06 Coupe
Later in 2015 Model Year - Grand Sport Coupe & Convertible
2016 Model Year - ZR1 Coupe
Based on information we have received, CorvetteBlog is holding to our statement made earlier that the 2014 Corvettes will begin to appear at dealerships in September 2013.

I was going to purchase my first Corvette, the 2012 Corvette Grand Sport. I attended the San Francisco Auto Show and saw the silver 2014 Corvette and the 2012 Grand Sport. I have been anticipating when dealers would know anything on or about it’s release date. I want to be one of the first, to place a deposit or buy the 2014 Corvette.
I’m not sure what you saw at the San Francisco Auto Show, but it could not have been the 2014 Corvette. Since you said it was silver, it may have been the show car created for the Transformer movie. The 2014 Corvette will not look like that. Any chance you can send me a picture AT bill@corvetteblog.com?