If they made Planescape/The Great Wheel the default cosmology in any capacity and made planar material for it... I'd mortgage my soul to be in on it. Just saying.
Please?
Hey, I more or less said the same thing and it got me in on Paizo's BotD III, so it can't hurt to try the same here. I can happily be invested in more than one cosmology and enjoy both.
Since this in a way is connected with GH, I'm going to comment on this.
For all of the complaints against 4e for it's gamist attitude, why on earth would you want to bring back the biggest gamist element from 1e/2e. The Great Wheel is one huge conceit to support the alignment grid. It was too cold, too calculated...too PRECISE. It had no mystery. It was too easily understood. If anything, 4e's cosmology injected a mystery and mystic sensibility to the planes.
Greyhawk and the Great Wheel are not synonymous. In fact I would put forth the premise that the cosmology envisioned by 4e would fit the sword and sorcery feel of Classic Greyhawk more than the Great Wheel. The titanic battles between Chaos and Order, capricious faerie realms, and creatures from the shadows.
The only thing missing would be a 3rd coterminous plane...a Spirit World. Something to replace the old ethereal plane, but intended more as the Spirit world of China or Japan, coupled with the Hunting Grounds of Native America and Purgatory. A place of nature spirits and lost souls unable to either ascend or descend into the afterlife.
That and have the the astral domain/dominion/plane of Hell fall from the heavens/astral plane to reside over the maw of the Abyss, only held aloft from complete oblivion by the will of Asmodeus.
I would rather WotC build something new with regards to a core campaign world. Something along the lines of the PoL setting "detailed" in 4e. Adjusted for what ever rules changes that may occur in 5e, and with a better designed map.
Failing that, my preference would be Greyhawk, especially the synopsis detailed by Mearls, and the original Blackmoor utilized. But only because my preferred world is Eberron, and even I agree that that should not be core. It's too divisive.
The Forgotten Realms/Mystara/Golarion all suffer from the kitchen sink syndrome. I look at Golarion and all I see is 2e Forgotten Realms with great art direction. All are too generic. To be honest, a reimaged Mystara that attempted a more sensible placement of the various cultures and countries would be a better than yet another take on the FR.
It must be the Blackmoor Theory. Everything is better with Arneson's Blackmoor.
