Well as with all tech, new features and advancements are always coming down the line. If AC is that important to you, wait.
I don't buy the argument that since new features are always around the corner one should simply buy whatever's available at the moment. This is not universally good advise for consumers, although one can see why manufacturers and retailers would want to promote this view.
While it's technically true, the reality is that technology in general, and computers in particular, don't evolve smoothly over time. Every year you might see some updated models with a bump in processor speed and a variety of other incremental features. But every several years you see a new generation product that provides much more than the usual incremental bumps.
Imagine buying one of these
just before this came out:
The new Retina MacBook Pro is one such example.
Anyone buying a Mac notebook over the last couple of years saw new models subsequently introduced with bumped up features. Nice, but nothing to get serious buyer's remorse over. But many who bought a Macbook Pro in the last year are going to have some significant regrets after seeing the latest model with a retina display, USB3 and Thunderbolt support, and an Air-like redesign delivering a dramatically slimmer and lighter device with no loss of battery life.
Smart shoppers will do some research before making such a large investment, to ensure that they don't buy just before a new generation product appears.