https://rpgbot.net/gen-con-2023-con-report-pf2-starfinder-2e-planescape-and-more/ said:
The Planescape box set includes a setting book, an adventure, and a DM screen. WotC heard the feedback following Spelljammer, and when everyone said “larger books, please”, they took that feedback to heart. Spelljammer’s biggest shortcoming was the small amount of content relative to the physical size of the box, and it appears that there is much more in Planescape.
The book which includes player options has 8 new feats. It follows the same design direction as Dragonlance: Shadow of the Dragon Queen, so there are backgrounds which offer 1st-level feats, plus 4th-level feats which have those feats as prerequisites. I didn’t have enough time to memorize everything, but one of the 1st-level feats grants a cantrip and permanent damage resistance to one damage type, both of which are paired and tied thematically to one of the planes. I believe it was called “Planar Scion”. The other feats are similarly themed around the planes.
The designers didn’t want to spoil the adventure too much, did share some details. A talking skull from previous Planescape content named “Mort” appears repeatedly. The adventure starts with players awakening in a morgue. The multiverse is a heavy theme throughout. Players are functionally immortal; reappearing as a different version of themselves upon death following specific rules which we didn’t have time to explore. The adventure runs from level 3 to 10, then takes a jump up to level 17 for the climax of the adventure.
We asked about the practical parts of how the level jump worked. The designers explained that most players never get a chance to experience high-level play, and that high-level play comes with a lot of complexity. By level 10, players fully understand their characters and their mechanics, so jumping to level 17 was seen as a gap which players could comfortably bridge without being overwhelmed. The design team knows there is almost no official high-level content, and they were excited to offer something in that niche.
WotC brought back the original Planescape artist, and it shows. The new art fits perfectly alongside 2e-era pieces, and really captures the same weirdness which has been the visual signature of Planescape. Among the art pieces, there is a train with a mustache and lips, and the art of said train was met with mixed opinions in the room ranging from “terrifying but hilarious” to “this is the pinnacle of locomotive technology.” The DM screen art features a githyanki, a green slaad, the lady of pain, an anxious-looking human woman, and a few other characters, and the whole thing has a wonderful, odd, cartoony feel that I’m very excited about.
Following the round-table, the designers had a few more minutes, and both Makenzie and Wesley stuck around to look through the products with us. Wesley talked to Randall and me about Planescape, and pointed out that the DM screen was the first time that they changed the art for conditions. Rather than the classic art of an ogre, there’s now new art including an unconscious modron. The screen also features quick reference information for the planes and for Sigil which will be helpful while navigating Planescape.