The potential of the credits is what drove the stock this year. Tesla makes $millions from selling the credits. http://www.arb.ca.gov/msprog/zevprog/zevcredits/2012zevcredits.htm
A big problem is that Tesla may have gamed the California law to qualify for more credits.
This document describes the law: http://www.arb.ca.gov/msprog/zevprog/zevregs/1962.1_Clean.pdf
A zero-emission vehicle gets 3 credits if it can go over 100 miles and 4 credits for 200 miles without any emissions.
The top vehicle class gets 7 credits if can go 300 miles and refuel in less than 15 minutes. Unfortunately for battery cars, even the fastest recharging takes about an hour. The top class was expected to be hydrogen cars or equivalent.
This is where the story gets tricky...
Tesla had a splashy media demo in summer where they showed a battery swap in a few minutes. Is a "swap" the same as "refueling"? Who knows. Tesla appeared to qualify for ~twice the credits.
Everyone believed the demo and the stock moved higher on anticipation of the extra credits.
I'm doubtful that an automated system could safely could replace a critical piece of the car in an Indy-car-like pit-stop.
Months later -- the Tesla SuperCharger network still isn't ready and the company has not built the battery swap facilities.
This is raising a big red flag for the stock. The company appears golden if you believe the media but the numbers are looking questionable.