Well the power of it's motor is unbelievable as it is(0-60 in 4 seconds........). Granted the vehicle itself is only about 2500 pounds, though. The way I look at it is that that weight is minus an engine, a gearbox, a drive shaft, and anything else you can think of in today's cars. But the power of these types of motors are only going to increase, and the capacity of the batteries increase with it.
take a look at this site
http://www.teslamotors.com/index.php?js_enabled=1
If they fixed up the styling a little bit it wouldn't be a half bad car....