It's a pr stunt for now but not that far off. 20 years after Paulraj invented MIMO, a company founded by his Stanford colleague Andrea Goldsmith is using 8 antenna MIMO to show the way to 10 gigabits on WiFi. Broadcom is promising similar. The real world results of "1.3 gigabit 802.11ac" so far are 400-500 megabits and the early results of "10 gigabit" will probably suffer similarly. But in 2-3 years, some homes will have effective WiFi speeds in the gigabits.
These speeds are based on 160 MHz of spectrum, only possible if few neighbors are using the band. 8 antennas will provide 8 separate streams in some locations but little more than 1 stream in others. MIMO separates signals by slight differences in reflection. That has the surprising result that the worst performance is when you have perfect line of site. Hakan Ericsson of Ericsson explained to me that MIMO gains would be very small in much of rural Australia because the terrain is flat.
IEEE has a very active standards group, 802.11ax, working on multi-gigabit WiFi. There's a wealth of information at the .11ax page. IEEE has a free mailing list that lets you track what's going on.