I've always noticed that Grey leather isn't available on the Model X. It's still my preferred colour for Model S seats. I noticed today that if you select Grey Next Generation leather seats on Model S, it quotes a USA delivery date of Mid 2017. Only with Grey Next-Gen seats. The other seat types all have delivery in 6 weeks or whatever. I wonder what this means? Will the grey seats get phased out? Unless it is a web site bug, they are obviously trying to avoid having to deliver grey seats!!! Alternate theory: in addition to 100kWh battery they are about to upgrade the Model S seats to a "Third Generation" seat that has perforation/netilation/cooling, call it what you will, plus perhaps a non-leather option a la Model X.