except for the price and 100mhz faster processor is there anything else different than on model from 2013 (i am asking since i bought 2013 model couple days ago :))
I think you can call Apple and get a free upgrade to the latest model if you bought yours within 30 days of release of the new ones.
Yep, they'll upgrade you. It's the same as returning the product and buying a new one. I think the return policy is 14 days though.
Along those same lines: be careful if you buy an Air at a retail store for a little while. It might be different now, but a few years ago when I got my MBP I waited until the day they were released, called to confirm they were in stock, and when I got to the store they tried to sell me one of the older models that were still in stock.
As far as we know so far, nope, no other differences. Maybe a teardown my iFixit will reveal something new but I doubt it.