Yes, the Performance version with Ludicrous mode was confirmed by Elon
here. For production start date, a few months ago Elon said end of March 2018
here, but then more recently he said mid-2018
here.
This won't be a software upgrade. The Model 3 P80D will have large motors in the front and rear. The Model 3 80D will have a smaller motor in the front. Also, the performance versions have a smart fuse that can output maximum power safely and quickly.
Ludicrous mode and performance version are the same thing for a while now. Initially, when they first discovered the smart fuse, the P85D's that were sold until then, didn't have it. So they offered to retrofit Ludicrous mode for $5,000. This was a hardware retrofit. Since then, the performance versions come with the Ludicrous mode.
The 0-60 time and the price of the Model 3 P80D are not released yet. My best guess is 3.1s and $74,000.
By the way, the most likely scenario for federal tax credits is as follows. More details
here.
Optimistic Scenario (65% likely)
- $7,500 for deliveries until Jun 30, 2018
- $3,750 for deliveries until Dec 31, 2018
- $1,875 for deliveries until Jun 30, 2019