10x or 100x more wireless throughput using many antennas. Masayoshi Son at Softbank has just deployed the first commercial Massive MIMO systems. 100 systems, each with 128 antennas, are being deployed in Japan. The early results show 6-10X capacity improvements. Some of the world's best engineers - Henry Samueli, Andrea Goldsmith, Arogyaswami Paulraj, Vint Cerf - expect ultimately MIMO will yield a 50X improvement. (That's not guaranteed, of course.)
Ericsson announced they'd be shipping 64 antenna systems in 2017. Huawei, ZTE, and Facebook have demonstrated 96-128 antenna systems. Each transmitting antenna sends a separate signal. The receivers mostly have two or four antennas. Each signal bounces off walls and other obstacles in a slightly different way, allowing the receivers to separate them.
Paulraj invented MIMO in 1993 and nearly twenty years ago predicted a 100X improvement in capacity at very little power increase. Many of us have seen a preview of what's possible from WiFi 802.11ac. That uses 4 antennas and triples performance under the right conditions. Add more antennas and enough processing power and almost anything may be achievable.