Its been just over 2 years and I am still perfectly happy with the performance of my Macbook Air (2011 model).
Right now I do not see any reason to upgrade. Although battery life is much better, I am around an outlet enough to not worry too much. The one thing that would probably make me switch is if they can decrease the bezel around the screen without reducing the structural integrity. If they could fit a 13" screen in the 11" model (or maybe slightly larger than the 11" model) I would be all over it in a heartbeat. Retina would be nice but not a must have for me.
I probably expect to realistically upgrade in another 2 years. Maybe then I will see a dramatic difference in performance (this is the first laptop I have used with an SSD, and if it still looks exactly the same I don't plan on changing computers until there is a performance difference similar to the jump from platter based hard drives to solid state).
That sounds like a great idea - thinner bezels would be awesome. I wonder if it would decrease the weight of the MBA too, if the bezel weighs more than the screen.
How is the 11" screen working out for you in terms of long-term use?
Seeing that I still have my Apple IIe in very good condition, and still serves out a great game of Lemonade Stand, Oregon Trail, Zaxxon, and Choplifter, as well as refreshes my memory on Logo and Turtle Graphics, that track record puts me on par with 'until the wheels fall off'.