Submitted by ddruz on 02. April 2013
Looks like they may be moving seat memory from the leather seats to the tech package:
Seat memory has been removed from the leather seats on the Options & Pricing page.
Seat memory has been added to the tech package on the Design Studio.
Seat memory has not yet been added to the tech package on the Options & Pricing page. No doubt they are a bit overwhelmed trying to get all the website changes synched.
Edited Apr 5: See my more recent detailed post below after receiving confirmation from Tesla.