We might get one in the next couple of years. It wouldn't be a Tesla, though! It would be our commuter car, since my wife's trip to work and back each day is only about 30 miles total, well within the range of say, a Nissan Leaf. Because we take longer trips pretty regularly, it wouldn't be practical to have it as our only car at this time.
I have to agree that it probably doesn't quite add up, yet. If we got the Smart Electric, at $25K (estimated), we'd save about $1000 a year on gas, at today's prices (7500 miles/year, compared to a gasoline car getting 30mpg). We could get a small gasoline car (like a Ford Fiesta) for $15K. It would take 10 years to break even. We have yet to see how much we could shave off the new car price with government incentives; if it's a lot, that could change the equation, as could a major spike in fuel prices.
I'm looking forward to improved battery technology and other power options to batteries, e.g.
hydrogen fuel cells (etc). When there are electric cars priced about the same as gasoline cars, with longer ranges (300-500 miles, say), then the game will change completely. But I do agree that the Tesla roadster is one sexy beast of a car! 0-60 in 3.7 seconds.