The first wave of 802.11ac routers currently available on the market are based on earlier drafts of the 802.11ac standard and will no longer be the fastest standard on the market. The second wave of 802.11ac devices are based on the final ratified standard and are set to include new features that better optimize wireless networks.
802.11ac standard: Wave 1 vs. Wave 2
802.11ac <a href="http://www.networkcomputing.com/wireless-infrastructure/80211ac-wi-fi-part-2-wave-1-and-wave-2-products/d/d-id/1234650