I have the 2011 model 11" Air and I've been waiting and saving all year for the new model, I desperately want the better battery life! I just ordered the base model 11" with the additional RAM. (Upped it to 8 gigs.) So the base price was $1099.00. With AppleCare ($249.00) and Sales tax (Glendale, AZ $144.00) and the $10.00 power adapter converter (so I can use my old extra chargers.) and the shipping ($14.00,) it worked out to just over $1500.00. I hope that helps you decide.
You could skip AppleCare for now, I think, and just pick it up within the year--(Somebody correct me if I'm wrong about that; that's how it used to be.) So your cost could be less.
But, for the extended battery life alone, I would definitely recommend you get the new model!