Best earmark a whole bunch of cash to re-invent the WLAN infrastructure again then! The shorter range of 60 GHz tech will mean i have to re-survey, and consider a higher density of devices... after I've probably already 'just' re-surveyed to change from 802.11n omni' antenna to 802.11ac downtilt antenna...
I wonder what best practice for backhaul will be... since it's unlikely that all those Gigabits will fit on a single switchport, over cat5e.