When the 13-inch Air came out, it was back in early 2008 and it had a completely different purpose. The 13-inch Air was the showcase of new tech, a laptop which represented the future, but which was impractical and expensive at the time. It had a slow hard drive and a slow processor, and no optical disk drive.
When the Air was revamped, in 2010, it kept the same screen size and also added another one, an 11-inch. It was in part a carryover of the previous model. Still, there were enough elements to differentiate it from the 13-inch Pro. The Air was thinner and lighter and had a smaller-sized but faster SSD, and no optical disk drive.
Now, times have changed. The 13-inch Pro became thinner and lighter, and also features an SSD and no optical disk drive. It is more similar to the 13-inch Air than it has ever been. The two models are very similar. You can argue of course that the Air is even thinner and lighter, and that the Pro is more powerful. But they both serve essentially the same purpose, something they didn't back in 2008 or 2010.
I don't see a point in launching another 13-inch Air this time, or a 14-inch model. I think Apple will launch just one model, with a 12-inch screen.
Of course this is all my personal opinion, and my impressions on this, as I think it makes economic sense and is in line with rumors and speculation here and elsewhere. I may be wrong, of course. If you think you have elements to believe that a 14-inch screen will be released, then go ahead. If it is just the product of your imagination, because you want so badly an Air with a 14-inch screen, then you may keep dreaming, but you should know that the probability of it being released is low.
