Still on sale does not conflict with being EOL :-) They will sell as long as they can, but just stop active development on features/firmware. And IPv6 still has a long way to go to become mainstream required.
But if they do start updating you won't hear me complaining 
It looks like ICANN will run out of IPv4 space in about 12 months and the RIR's in about 18. Don't know how much "end user"/consumer software is v6 aware, but it would be nice to be able to test such things and do evaluations for dual-stacking, tunnelling and other transition testing.
I've been trying to figure out how to allow ICMPv4-Type8 inbound for tunnel creation and the docs with my 655 are *sparse* on stuff outside of gaming.