I believe Elon has made some sort of reference towards designing a cargo van also, with the caveat that it was an 'in the future' type thing, ie low priority. There are those (myself amongst them) that expect one of the variants of the Model 3 platform to be a small to medium utility van that competes against the Renault Kangoo, Volkswagen Caddy or step a size upward and take on the Ford Transit, VW Transporter, et al. I would personally love to see this - these vehicles are super practical, efficient and would have the natural benefit of the added packaging space that comes along with the Tesla platform architecture.
I'm no expert on this but it would seem the American market in particular is a low dangling fruit for Tesla. Ford sold 103K Transits last year, and thanks to the chicken tax this particular market lacks compelling foreign options like the Volkswagen Transporter and Hyundai iLoad, both of which move more metal here in Australia.
So, in swoops Tesla with a competitively priced all American alternative that costs a fraction to 'fuel', has access to the SC network, features nifty technology and has a trick or two up its sleeve, as you would expect from the plucky little Silicon Valley startup. Dominance in this segment would translate to 100K+ domestic sales per year - a very tempting target for an automaker focused on the magical half a million cars per year mark.