Phlogiston is gone man. I am a big SpellJammer fan and DMed it back in 2nd edition and am even DMing it right now with Fourth Edition. Even if you don't use Fourth Edition you should check out the planer books for 4E. The Astral Sea is one of the best innovations of the whole 4E era. Makes perfect sense for SpellJammer and much more sense than the boring empty void described in 1e/2e Manual of the Planes. Arcane Space was a weird conceit that worked mechanically OK but it never should have been invented. It was created by a TSR that thought they could do science fiction television shows and cartoons. Spelljamming ships sailing the astral sea is awesome stuff and likely to remain in fifth edition. It still works with the Great Wheel cause you can sail around it.This was definitely a fun rumour back in the day, but, Athas and Toril are separate worlds, each in their own crystal sphere (Athas in a closed one) floating in the phlogiston.
And yeah, originally Athas had a blue sun and was ruled by psionic halflings, all the other races and magic came later (and yellow, then red sun).
Phlogiston is gone man. I am a big SpellJammer fan and DMed it back in 2nd edition and am even DMing it right now with Fourth Edition. Even if you don't use Fourth Edition you should check out the planer books for 4E. The Astral Sea is one of the best innovations of the whole 4E era. Makes perfect sense for SpellJammer and much more sense than the boring empty void described in 1e/2e Manual of the Planes. Arcane Space was a weird conceit that worked mechanically OK but it never should have been invented. It was created by a TSR that thought they could do science fiction television shows and cartoons. Spelljamming ships sailing the astral sea is awesome stuff and likely to remain in fifth edition. It still works with the Great Wheel cause you can sail around it.
I am not a fan of what they did with Forgotten Realms but the Dark Sun World material was pretty good. Originally they made some big mistakes with DSW and basically invalidated their entire boxed set very quickly (during 2E). The Dark Sun themes were an excellent use of the 4E rules. Also, Dark Sun works a lot better under 4E. It matches up nicely. A lot of the new planer material is fantastic and I fully expect most of it to be retained. Not talking about the whole Dawn War back-story but rather implementation of the Shadowfell, Astral Sea, etc.No offense but that is so far from the original source material it ios not really Spelljammer anymore. On of the main dislikes of 4th ed was how they screwed up the older campaign settings and thought that their new and improved ways were better. Market proved them wrong. Original DS is better than 4E same with Spelljammer, and FR.