It seems that WotC are re-releasing Planescape for D&D5e in 2023.
Planescape is one of those things that never really seemed to live up to its promise. I found the concept interesting, and I really enjoyed Tony diTerlizzi's art, but it didn't go as far into The Weirdness as I thought it should. I doubt that it will be any different this time around either, though 5e's nature as an over-the-top cinematic superhero game could suit it.
All of these D&D settings are, of course, heavily reliant on the DM for their realization, but I feel there's something missing from the Planescape milieu, and I don't know quite what that thing is.
Also, I absolutely hated the cutesy patois they scattered all through it.