Current smart phones do more than I would have ever expected. The evolution is impressive.
But, probably faster, more memory, higher resolution screens, all linked to a faster network. More standardization of apps so that IOT devices can talk and be controlled from your phone.
They need to do something about the terrible keyboards. Voice recognition helps.
Smart phones will never take over the PC/workstation/laptop market unless they can improve the UI so a college student can type a 500 page thesis paper as easily as a desk top or lap top.
Oh, another idea: cell phones that can detect the DNA of the fish you are eating so you can check that the seafood restaurant you are eating at is not serving you Cambodian ratfish instead of Red Snapper.