There is no way it's the end of the MBA. Apple will use the MBA form factor and design with its other Mac notebooks. Even when the MB and MBP look more like MBAs, the MBA will just get more ultraportable.
Apple isn't going to EOL the MBA. It seems obvious a new MBA will follow the same suit as the 13" MBP. Look, Apple uses one base configuration set for five Macs including the MBA - 13" MBP, 13" MB, 13" MBA, Mac mini, and 21.5" iMac. Since the 13" MBP is Apple's biggest seller, it got the update first. As soon as the demand and inventory of the 13" MBP is covered, the MBA will have its turn getting made with its new components.
Definitely still a C2D CPU, Nvidia 320m GPU/chipset, and some other needs for the MBA.
If Apple were going to EOL the MBA, it would probably just keep selling it for the exact same price for a few years. However, with Apple's long term strategy of Macs being focused primarily on notebooks, and people wanting lighter and more energy efficient ultraportables, the MBA is set in the lineup for a long time to come. It doesn't even matter if sales are where Apple wants them or not. The design is too critical for the future of Macs. Apple can learn a lot from the designs by continuing to sell them and making them more relevant.
I will be shocked if the MBA goes anywhere except more ultraportable over the next five to seven years.