No idea, mate. There was supposed to be another wave, which would have included "The Brasher Doubloon" (an Eddie Muller commentary had already been recorded), plus they still hadn't reissued the previously-pulled "Boomerang." I don't believe there's been an actual announcement that the line has...
This is Warner we're talking about, not Universal. I'm sure they'll use dual-layered discs with two films on each disc, just like in their Val Lewton and Masterpieces of Horror sets, with "double-feature" covers... which is just fine by me. Bring 'em on!