My first post, so please forgive it I screw up any of the forum conventions.
As someone who has been lurking for two years waiting for the long-rumored AWD announcement, I am a little surprised people have been so shocked about the safety features and the dual drive. I'm just your average fan, and it was pretty obvious to me that the development of the X would bring a lot of new features to the S, particularly for safety issues that are more pertinent to the SUV buyer.
That said, I completely understand where the September buyers are coming from. What happened to them, quite frankly, sucks.
But here's the thing -- if you're going to complain about what Tesla did, you have to suggest an alternative way for Tesla to launch major upgrades to the product line without taking a hit on new orders. As people here have posted out, if Tesla makes an announcement that BIG THINGS are coming, they might as well shut the factories down until the new innovations are ready.
Plus, even if you could figure that out, you're left with an unsolvable dilemma -- someone is ALWAYS going to be last. Regardless of when the announcement comes, there's going to be somebody who just got delivery of the "now-outdated" model. Always. And they're going to be just as ticked off as the September buyers are.
I will probably be blasted for the solution suggested would be that Tesla adjust its approach to act a bit like a big domestic car company instead of constantly innovating the hardware/software but...
The only way I can see the that would make the no-surprises buying pool happy would be to slot into a model year release concept. All the "innovate now, innovate fast" folks would hate that and so would Tesla Motors since they would probably have to take a hit in sales by doing so (along with a hit in stock price).
With many of the other domestic brands, everyone knows when the new model years arrive, and what the feature set will be, along with the new prices.
As the old model year comes to a close, the prices start to slip and the units dwindle off. Last year models sit around for a bit for even a more discounted price and get snapped up by the discount buyers that won't bite otherwise.
Buyer's win mostly. Tesla (who at this point in their history can't make enough cars quickly enough anyway) loses.
So this will never happen.