Can you smell it? There's fresh silicon in the Air. The MacBook Air 13" Early 2015 contains:

5th generation, dual-core Intel Core i5 processor with Intel HD Graphics 6000

128 GB flash storage (configurable to 512 GB)

4 GB LPDDR3 RAM, configurable (but not upgradable) to 8 GB

13.3" 1440x900 pixel display (~128 ppi)

802.11ac Wi-Fi connectivity

Thunderbolt 2

Dual microphones