TSLA may intend to debut battery swapping with the trucks, where the large physical form factor might be more amenable to swapping. While the range is low, if the equivalent mpg is higher, and the energy recovery from braking significant enough, then it would pencil out as an financial advantage to use the electric truck.

A Yahoo Answers post [1] gives an idea of the kind of metrics TSLA will have to soundly beat. Fuel is the biggest cost. Bring that down and you'll get the trucking companies' attention for the pitch.

Not all semis are long-haul; there are local delivery semis that fit into the 2-300 mile range, and that could be an initial market.

[1] https://answers.yahoo.com/question/index?qid=20100327005347A...