From reading all of the anti-TSLA articles and blog posts, the short folks don't necessarily think Tesla will fold in the next few years, just that the demand for higher end EV cars wont be there after us first 10,000 buyers pony up the $60-100K for our cars. The Prius probably didn't make financial sense for 90% of the million or so folks who bought one, a Yaris or Corolla would have saved more money, but people want to a) feel like they are helping the environment, b) make a statement to the friends/family/customers/etc c) set an example for their kids d) stick it to OPEC/help our country stop being so dependent on oil...
I see waaaaaaay too many new E550's, 550i's, A6's, LS460's, Panamerra's etc running around SoCal, so I know there are are still many financially stable folks just in my part of the state to keep Tesla busy making the Model S for a very long time. Once these buyers realize they can save thousands a year on fuel, never need to stop at a gas station, can access our states HOV lanes, start the day with a full tank of gas, etc, I think Tesla's waiting list will stay pretty long. Without a single cent spent on advertising (aside from stores in nice malls), Tesla will have sold out for the first 12 months of production before the first car has even rolled off the assembly line, and we're not talking about a limited production of 500 Ferarri's, but 10-15,000 cars! What's going to happen when each of us 10,000 buyers shows the cars off to 50 of our neighbors, coworkers, family and friends? Tens of thousands of more sales. Finally, having seen what a great management team and facility Tesla has Fremont, I think the X and their upcoming $30K car will be just as popular, if not more. I trust Elon when he says they can make 25% margin on these cars, which Wall Street will absolutely love.
Tesla isn't trying to be company that pumps out 500,000 cars, heck, with the 40-60K they might be making three years from now, that won't even put them in the top 50 of manufacturers according to this document:
http://oica.net/wp-content/uploads/ranking-2010.pdf, but I think the growth and profitability will keep this stock soaring for a long time.
I'm long on TSLA, and my only worries are that a global economy meltdown takes down the whole market, or that some supplier related glitch delays things, but going back to Tesla's management team, I think they are sharp enough to have planned accordingly, or can find a workaround if need be.