I don't think it'll happen because I don't see it as being that obvious... how often is a tank sitting next to a plane on the flight line (which most wooden bases end up resembling)? Unless you're doing a diorama of a crash, airshow, or museum, I have a hard time envisioning the need for them to be side by side.
Helos, on the other hand, could easily be envisioned next to a tank, and are (sometimes, though more often than airplanes) available in 1/35 scale.
I'd personally like to see more flightline vehicles (jeeps, humvees, misc. cars and trucks) in the airplane scales, and would guess that this is the way things would go (if they went).