Tesla CEO Elon Musk said in October that all models built from that point on would contain the hardware capable of Level 5 (read: full-on) autonomous driving, but none of its systems would be enabled until a later date. It appears that rollout will begin in December.
Over Thanksgiving weekend, Musk responded to a question about the Enhanced Autopilot rollout, and he said it would begin in "about three weeks." The rollout will be an incremental one, taking place over a span of months, so don't expect the first part of that plan to be Earth-shattering in any way.
In all likelihood, the first stage of this rollout is likely to bring Tesla's new Model X and Model S vehicles in line with the older Teslas currently on the road. As the Enhanced Autopilot cars rolled off the line with all their active safety systems disabled, including adaptive cruise control and autonomous emergency braking, the first update will probably enable those features for owners.
For those of you hoping to see Level 5 autonomy arriving before the end of 2016, you're setting yourself up to be disappointed. Full-on autonomous driving, although it's been previewed in videos recently, won't be ready until next year at the absolute earliest. I wouldn't expect these updates to amount to much until midway through 2017. Tesla did not immediately respond to a request for clarification regarding Musk's tweet.
All Teslas in the assembly pipeline are now built with eight cameras, 12 ultrasonic sensors, a forward-facing radar and a beefy Nvidia Titan GPU, which the company claims is enough to enable Level 5 autonomy. The car does not include lidar, which works like a radar system but with laser light, despite other companies' belief that it is an integral component in autonomous driving. The system will also be built into the forthcoming Model 3 sedan.