This is the case with the electric sports car from San Carlos via Hethel. A few days ago, CEO Martin Eberhard sent out a letter to the 380+ customers who have already paid up to get a Roadster, letting them know that the original 250 mile range target wouldn't be met. Instead, Tesla expects the final number to come in somewhere above 200 miles, which is still very impressive, even if slightly less so than originally expected. AutoblogGreen has more information.
[Source: Tesla Motors]