I kind of miss it and I am happy it is gone, and I think it is not gone enough (or rather separated enough about 'neutral' planar concept of 3rd edition).
I explain. I strongly disliked whole idea to re-place what planes used to be. Planescape doesn't have feeling of universal planar system and it's own neat language use felt kind of cheap rip-off of popular supernatural/gothic games of era, not to mention art-style, and Factions (Like Prides in Immortal, or Clans or Tribes in White Wolf's game). Werewolf the Apocalypse was out 1992 (or 1991), Immortal the Invisible war 1993, and we saw Planescape 1994. If I hadn't run into those elements in games many times over, I'd thought it cool, but I had, and it made them feel lame. However, still, I liked few ideas, and many adventures and products had interesting unique feeling, in workable good way. Certainly one I had not used to see in anything by TSR.
However, I hated it, because it re-placed old planes, and didn't IMO do that very well. Planes are supposed to be universal, but Planescape was not that. It was were specific 'microcosmos'. Many of it's new ideas weren't universally compatable anymore. They worked with few worlds, but not even every campaing word TSR had created.
At the time, I had anxiously been waiting for new 2nd edition planes book, but instead I got *this* new game world, not expansed version of old planar book, that I had been expecting.
So, even while Planespace had been interesting game world in sense Dark Sun, or Ravenloft, or Forgotten Realms was, it was not about planes no more. Not truly.
Spelljammer, at least, didn't try to replace anything. It was new idea, yes, but easily dismissable if one didn't like it, or in as my case, found it not fitting to one's game world.
It left elements of it's 'corruption' as I call it, to new more neutrally usable 3rd edition Manual of Planes. Like originally chaotic neutral Githzerai (Fiend Folio, 1st ed AD&D) living in Limbo, suddenly being lawful neural monks living in Limbo still (Yeh, sure) to mention one
What comes to some things, they are just matters of taste. I hated idea of Bloodwars, many liked it. I hate idea of Sigil (its setup and how important it is, not how city otherwise was), but many people have been quite happy with that. These were things I probably wouldn't have even paid attention to, however, if Planescape hadn't been presented as new edition of old 'Manual of Planes'.
However, it would be nice for some publisher to pick it, but in that case I'd like to see it presented in particular world's cosmos, not something everywhere.
Planescape has much good material, and it would be sort of shame to let it lie there, and I would be curious how it would turn out to be in its new incarnation.
I certainly would pay at least first book made, to see, if nothing else.
