It's really all just speculation and rumor at this point. It is possible that there could be a 12" MBA that is the same size as the MBA 11" with smaller bezels. and the 13" upgraded to a retina display. There's a significant size difference between the 11" and 13" and a need for both sizes.
As I have been suggesting to folks, if you're looking for a MBA in the near future, get your cash/credit card ready so you'll be in a position to buy the new models if they fit your needs, or buy the current one.