mhacdebhandia said:
There is no reason to keep the Great Wheel in the core rules except tradition, and maintaining tradition for tradition's sake is not justifiable.
On the contrary, adherence to tradition is a good thing in and of itself. Traditions can be changed, but it's not justifiable to do so without a powerful reason.
Adhering to traditions produces a number of advantages - it helps us use newer accessories with older ones. It allows older themes and plotlines to be brought forward and elaborated it on in newer adventures and sourcebooks. It introduces worthy elements to a new generation of gamers. It makes those of us who were fans of the older material happy, and doesn't make any difference one way or the other to people who didn't care much about the planes.
Mining older canon is, in any case, a very enjoyable pastime.
Novelty for novelty's sake, on the other hand, isn't justifiable.
I agree with those who've said that there will probably be substantial 3rd-party Great Wheel support. Necromancer Games has its own idiosyncratic planes, though, so it's an unlikely candidate for this, the Hells and Abyss and City of Brass excepted. We'll see, though.
A lot of us want specifically to see WotC's IP elaborated on and reinvigorated in new products, new online Dragon articles and so on. We don't care about generic versions of Gehenna - we want to see the D&D Gehenna, with its mysterious general, its Tower Arcane, ts lich-lord Mellifleur, its barghests, the frozen realm of Loviatar, the abandoned realm of Iyachtu Xvim. With a new default cosmology, this is less likely.
I think it's unlikely that the Great Wheel will be found in a hypothetical 4e Greyhawk or 4e Planescape. It seems more likely that they'll use the default cosmology, as it
does overlap with the Great Wheel substantially. The new "Astral Sea" has a Pandemonium, a Nine Hells, and probably every other plane except for the Abyss.
I think a substantial amount of the older material
will be carried over to the new default, but the amount of twisting and rationalizing will make things awkward both for the professional designers stuck trying to make sense of the resulting mess and for ordinary gamers trying to either use new material with the old stuff or old material with the new.