The City of the Gods is what sets this setting apart, a sci-fi society that summons demonsBlackmoor: The first campaign setting. The big question here is "Who has the rights? WotC, Arneson's estate, someone else?" Also very generic. What sets it apart?

As a Greyhawk fan, a huge part of me hopes they never touch Greyhawk again. The desire to modernize the setting does not sit well with me.Greyhawk: The birthplace of adventure. I don't think there's anything that sets it apart from other settings. However, it's where the classic dungeons come from and it's iconic. If it was to come out, next year would be the time since it's the 50th anniversary.
Kara-Tur: Fantasy East Asia, once published under the name "Oriental Adventures". Part of the Forgotten Realms. You might be able to get a cool wuxia-flavored adventure here, if handled correctly..
These are technically supported as part of the Forgotten Realms. WotC just refuses to acknowledge that anything outside the sword coast exists.Maztica: One of D&D's takes on fantasy Mesoamerica. Lack of appeal. Not enough broad appeal. Might be best reserved for DMs Guild or fan content.
This is one that didn't age well.Mystara: The world of Basic D&D. This is a setting of settings, which include the Known World, Hollow World, Savage Coast, Red Steel, Thunder Rift, etc. Some classic adventures hail from here. It's got the gazetteer series (some good, some bad), a ton of real-world analogues, skyships, new races (where the tortle came from!), and more. The setting suffers from not being a cohesive setting. It's generic and doesn't fully stand apart.
The problem with Nentir Vale is that it's such a small setting that never got significant expansion. It's like a starter setting, rather than a real one. If not for the Axis cosmology, it would be easier to drop into an existing setting.Nentir Vale: The setting of D&D 4th edition. Fairly generic, but some cool ideas in here. Personally, I'd have this be part of Exandria. I know, I know, that's a crossover. I could see an adventure set here.
"Other parts" of settings never seem to get attention beyond the casual mention. The only reason why there's so many settings in FR that got attention is because they were originally not part of the realms. IIRC, only Maztica was written specifically to be part of the Realms.Taladas: The other continent of Dragonlance. There are some neat geographical features here, but in some ways, Taladas came across as the "anti-Ansalon." It lacks a lot of flavor that makes it Dragonlance. I don't see WotC investing money in this. Best left to DMs Guild and the Dragonlance Nexus (gratuitous plug).