The Model S will not
'drop in price' with the advent of the Gigafactory. Tesla Motors will likely see a lower cost for batteries by that time, as production of Model S and Model X will top out in 2016 or 2017. So they will see an improved profit margin, and that will allow for the expansion of the Supercharger network. If, as I presume, the Model ≡ arrives with a 60 kWh battery pack as standard, there is a strong possibility that the Model S 60 will go away. If, as I hope, a higher capacity battery pack is offered, then the 85 kWh battery pack will become the entry level for the Model S.
I wouldn't expect Tesla to introduce a new sedan series between Model S and Model ≡ either. There will be no direct competitor to BMW 5-Series or Mercedes-Benz E-Class anytime soon, if indeed ever, from Tesla. They have no need for a
'tweener' vehicle offering.
I would like to reiterate that Tesla Motors does not make luxury cars. Everyone who is hoping for an
'improved interior' full of
'luxury accouterments' is likely to remain disappointed going forward. Tesla makes engineered interiors -- not crafted ones. You may get a better set of options to take care of some interior aspects, such as
'missing' cupholders, vanity mirror lights, grab handles and storage bins... some day. You will never get the cushy, buttoned down, folded leather, quilted, overstuffed interiors that are associated with
'luxury'. If that is what you are waiting for, you'd might as well put in your down payment for a Mercedes-Benz, Cadillac, or Jaguar product today. If you want that type of interior experience in a Model S, you'll have to invest in a trip to a professional vehicle customizer such as
West Coast Customs. I'm sure they would appreciate your business.