@Sylvie Barak: too bady today you have the FusionChips Party at Santana Row, otherwise you could have attended the IEEE Comsoc's meeting on a relatedf topic of Outdoor Wireless Networks for Smart Grids in which the city of Santa Clara is looking to use a 802.11x variant for free WiFi access to residents.
More dedtails at the link below if any one is interested:
QoS support in CSMA/CA system is very difficult to achieve although various groups have put a lot of effort into making it happens.
With the help of beamforming, if number of stations in a given coverage area can be estimated, maybe, QoS will be more achievable.
Hopefully they will include hooks for QoS support. Capacity for more streams is important, but ideally 802.11ac would support the capability to reject requests beyond its capacity rather than just degrading.
Once again, the IEEE will be slow to ratify a new flavor of the 802.11 standard, and consumers will be buying new equipment based on a "draft" standards. As long as the stuff works, I intend to be an early adopter of 802.11ac -- ratified or not.
Likewise (I think): "The system, which would apparently be backwards compatible with 802.11n systems, would use a three-by-three antenna operating at 80MHz,". Should read operating with 80Mhz channels in the 5Ghz band? I think that would be correct.