Looks like the next stage of wifi is moving from "n" to dual bands where "n" is available at both 2.4 & 5mhz bands simultaneously thereby allowing video streaming to use one band & general web the other and also making more channels available to cut down interference.

If this is just a different wifi card attached to the main motherboard in the router - wonder when Draytek will upgrade the 2820 with this The ability to select between 2.4 & 5 is already present in many Intel mini pci cards used in laptops from what I can work out.