It seems he wants to get back in to the live action production side of things. The filmed that just got picked up by Warner Bros. is called “Timeless”. Supposedly storylines are being kept quiet, but is said to be a mega budget time travel story.
Also, Zemeckis and his company have been talking about ideas to do another live action Superman film. I would love to see Zemeckis dive into the DC universe and see what he creates. Hell, his Christmas Carol had Jim Carrey flying all over LONDON, that I thought it was Superman for minute.
And of course as I mentioned earlier, the Roger Rabbit sequel is still on the table which you can read about HERE. So tons of cool films could possibly come to life through Zemeckis.