Keefe,
sorry but I enjoyed the humour of it.

Dark Sun and Ravneloft are dark and gritty/macabre.
SPelljammer was "
UP AN' AT 'EM, LADS!"..a
high. Which is good.
Real life, even in the darkest moments has humour. That's not a bad thing.
I love the nasty brutality of Dark SUn,and I love the humour of mad gnomish ships, machinations of the neogi, giffs as "Colonel Blimps" (old fashioned, stuffy, but honourable and loyal), the arrogance but fraility of the Imperial Elven Navy, and so on.
Sure better, easier rules, enjoying the fantasy, will be fine by me. But see why folk liked Pirates of the Caribbean, and what can echo into Spellaming for 4th ed
Sure, "astral jamming" will be great, so it's not confined ot just space (or the astral only).
Lot of folks have a bad problem caused by Star trek and the Space Race making folk think that space has to be sci-fi...when fantasy has been out there a lot longer!
Also, Spelljammer was so "Big" it expected and needed a lot of input from the players to enjoy it.
Shroomy,
well the devs have siad they want to bring old settings back, so long as it's done well, I'd expect ot see Dark Sun, Spelljammer, Ravenloft and Planescape in the years to come.
what really narked me and many folk off, was that TSR forced those settings to fit with novel releases, and selling more and more expansions that totally messed up the core settings and ethos.
So Dark Sun lost half the sorceror kings and it had a democracy (WTH crap was that?! A
democracy on Athas?! lol)
Ravenloft got added to and torn apart about 3 times iirc.
What a mess.