As we've previously reported, Tesla has boosted its income with the sale of ZEV credits from the get-go, but according to Darryl Siry at Wired's "Autopia" blog, those halcyon days in which credit sales accounted for $8.5 million (85 percent of the company's total gross margin) may be over. With everyone from GM and Nissan to Honda, Ford and Toyota promising full electrics within the next couple of years, the value of Tesla's ZEV credits are poised to plummet. The California program doesn't distinguish between a credit for a single electric in a fleet full of gas-guzzlers and a credit for an EV in a fleet composed solely of the same, so the 150,000 Nissan Leafs that the manufacturer will be able to produce by 2013 -- at three ZEV credits each -- will flood the market in a way that severely devalues whatever credits Tesla can offer from its low-volume Roadster model. Even when the upcoming Tesla Model S sedan -- which is expected to be priced at around 60 grand, minus the applicable federal tax credit -- hits showrooms, the credits on the market from the other manufacturers will have the same devastating effect.

Tesla, for its part, has largely ignored the upcoming sea change, with both the company and Morgan Stanley, which underwrote Tesla's IPO, citing a $5,000-per-vehicle ZEV credit profit in their public-offering presentations -- a figure not expected to hold up given the upcoming spate of competition. If Musk does in fact want his company to operate more like a Google or an Apple than a GM or a Ford, he'll have to face the entirety of a changing marketplace, not just the aspects that are convenient for his brand.