If you're interested in undrestanding ZEV credits and its impact on Tesla's bottom line ($5000/car) read bellow [1] Also, worth noting other automakers are slowly catching up. Remember Tesla had a big start with their roadster, but expect fierce competition from Japanese and European automakers. Which is all good for consumers. 1 : http://www.wired.com/autopia/2010/08/tesla-subsidy-vanishing...
Tesla owns key energy management system patents. Disclaimer: I'm super-long TSLA.
I also think Tesla has a bright future. But I hope they're relying on their brand value rather than transient advantages like patents. If I hear from Musk that he thinks their patents are going to be competitive advantage, I will be factor that (negatively) in my opinion of the company's prospects.