First, kudos to the artist Mark Stehrenberger for his rapid development of Tesla pickup truck drawings. They look lovely and fun, but they also look like (1) a Subaru Baja, (2) a Holden Ute or updated El Camino, or (3) a Chevrolet Avalanche, which suggests to me that Mr. Stehrenberger took some of his older designs over the years and re-did them, especially since only the 2nd drawing has a low-profile camera instead of large paddle mirrors. I expect some insane innovations if Tesla heads in this direction, like a sturdy yet retractable or dynamic roof rack (cuts down on wind resistance) and a weight balance that takes advantage of the whole vehicle, not simply the rear axle. I also expect the vehicle to be highly modular, as a service vehicle.
Elon said "electric truck that could be a real improvement on truck technology." What he did not say was "pickup truck." I think a pickup truck would be great, but I think a heavy freight truck would be epic. I also think that a freight truck would fit better with his comments about transport independence.
Given the time-line Tesla has, this makes more sense to me than a new consumer vehicle. If Tesla is even 3 years out on a pickup truck, Nissan is only 2 years out, and will likely build on their existing truck platform. If Nissan switches to a different battery design, which I expect will happen, then as a pickup truck, Tesla Motors will have difficulty competing. Additionally, pickup trucks receive significant wear and tear, and might be hard to manage in a service contract like what is offered for the Model S.