I'd take a more expensive dual-release over none at all though. And you never know, I might even find a 4K version that looks better on my TV than a good 3D one does (I have a 4K OLED, with gorgeous passive 3D) so it'd be in their best interests to try to convert me.
Andre
its nice to have both options
non 4k fans can sell the 4k disc and get most their money back, and vice versa with the 4k only fans can sell on the 3d disc.
would make it hard to know who is buying for the 3d or the 4k though but it might boost 4k poor disc sales (slightly...)