ABI Research's director for mobile-networks research, Philip Solis, foresees a day in the not-too-distant future when 802.11ac takes over the dominant position in wireless LAN technology. ABI's research focuses on the chipsets for WLAN. In summarizing the findings of its recent report entitled "WiFi Chipset Evolution: From 802.11n to 802.11ac and 802.11ad," the company says the "ac" protocol will see small shipment volumes in 2012 but a significant jump in 2013. By 2014, "802.11ac will emerge as the dominant WiFi protocol," the company stated. It added, "Only a niche subset of 802.11ac will be single-band 802.11ac, using solely the 5-GHz band. Most will be 802.11n/802.11ac dual-band chipsets."
Solis said, "With the small and dwindling number of 802.11g chipsets, everything has already shifted to 802.11n, and it has happened faster than most people expected. This is a clear indication of what will happen with 802.11ac. The 1x1 version of 802.11n replaced 802.11g. A rapid transition will occur with 802.11ac, but without the messy politics that slowed down the standardization of 802.11n in the past."
ABI says established chipset vendors will try to keep or grow their market share by transitioning as quickly as they can. Smaller vendors will try to expand their share of the market by quickly shipping chipsets with competitive protocol, band and MIMO combinations.
You can find more information on ABI's report here.