In Tequila Sunrise's thread, I introduced my ideas for an alternate Arcadia concept that I'll repost here shortly. Be warned, there's a long post ahead!
I've noticed that some planes get a lot more love than others. Baator and the Abyss see tons of action time. The Lower Planes are generally more adventure-encouraging than the Upper Planes. The Inner Planes barely get any canon attention at all compared to the Outer Planes. Even in fanon, some planes just get more love than others.
I took a step back one day and brought this concern up with a planewalker friend of mine. After discussing with him, I came to realize part of the cause for this problem I saw. As much as I love the Planescape setting, some of the planes are just plain boring.
Whether it's due to lack of developer attention or just that a plane's concepts haven't been explored deeply enough, some planes really are dull and uninteresting as a whole. Other planes teeter on the edge between boring and exciting. Most planes have a lot of overlooked potential that was never properly or thoroughly explored by the writers. Many of these "boring" planes have tons of neat little sites or they have a great baseline concept, but fail to come through as a solid unit when lined up with the whole setting. This leads to a lot of planes being "superfluous" or "unnecessary," which is a major criticism of the Great Wheel cosmology.
I've actually talked with my friend about doing something like this for a few months, but after getting positive reeception from the other thread, I decided to start up my own thread and see if folks are willing to jump on board and help me make a very long-term community project out of it. Basically, I love the Great Wheel and I love all the planes in the Multiverse, but I think some of them need a lot more love than others to really shine. Many planes give us a decent foundation, but the foundations need to be built on, and that's where the Planar Renovation Project comes in. We take the foundations and the existing structures, build onto them, knock down walls, sometimes bulldoze the entire structure back down to its foundations, and then build up again.
As I see it, there are two main problems with the "boring" planes. Not all planes have both of these problems, but most of the less-used planes have one or the other.
First, a lack of major conflict. Anyone with even the remotest understanding of storytelling understands that conflict makes the story. From the time we were kids watching cartoons on Saturday mornings until now, we intuitively enjoyed shows, books, and entertainment that expressed a conflict. Simply put, world peace is boring. Nobody writes movies or shows or books where everyone gets along and lives happily throughout the book without a fight or a tiff. Why? Because there's just nothing to write about. The Prince and Princess live happily ever after for a reason. The real story is how they get to living happily ever after.
What makes some planes boring is the lack of a clearly understandable conflict that wholly or partially defines the plane's existence. Some planes, most notably the Lower Planes, exhibit conflict in spades. Other planes have conflicts within them, but not conflicts that help distinguish the plane from others. So we get planes like Bytopia that are pretty to look at and might have a little bit of minor, localized conflict, but really don't do anything to convince most people that it really should be on the Great Wheel at all. The Inner Planes really suffer from this, but not from lack of potential. Most of the elemental planes have intra- and inter-planar conflicts that were mostly glossed over or underdeveloped by canon. Some of the Inner Planes have no real conflict at all, and the concept of a plane existing because it does isn't a terribly exciting prospect.
Second, a way to really differentiate from the Prime. The Multiverse is a fantastic place, but many planes don't really offer a whole lot that you can't get on a Prime world. This is a much, much more difficult issue to address, and takes a very secondary role to the first issue. What sets a planar adventure apart from a Prime adventure? The influence of belief is great and the Planes offer a variety of environments, attitudes, and concepts. Unfortunately, some planes don't do a very good job of portraying all of that in a way that makes a player feel like he's standing on some vast new world that fully embodies the concept instead of on his home Prime. Again, this problem is harder to tackle and in some cases may not be something that can be addressed. Furthermore, the Lower Planes suffer from this much less than the Upper Planes do. Even some of the Inner Planes get this problem.
Sigil, to me, is the only part of Planescape that doesn't suffer from this at all. Sigil is thoroughly developed enough and unique enough to be an incredibly powerful adventure land in its own right. The City of Doors has enough flavor to carry the setting entirely, but unfortunately that comes with a Great Wheel that could use a little bit of help.
All that being said, I have to reiterate that I love the Planescape setting. I wouldn't be here if I didn't. But there are parts that feel unfinished or just plain lacking. So the Planar Renovation Project seeks to go around the Great Wheel and the Inner Planar Sphere, take the foundation the wonderful Planescape writers have given us and work up from there to reduce the "superfluousness" and increase the appeal and character of all the Multiverse.
I've got Arcadia posted up over here for you all to take a look. It is my hope that others will want to jump on board and help with the development, provide ideas, and otherwise get involved. This would be a very long-term project, so there are no real time commitments or demands. Still, all are welcome to include their two cents and I think we can all work to help out the Multiverse and really give the planes the character they deserve.
In some ways, the upper planes should be relatively conflict-free. After all, the good beings try to avoid harming each other. Some conflicts may occur because of differing beliefs, but the inhabitants are more likely to try solving things without violence.
Of course, one possible source of conflict on the upper planes is evil creatures invading for a particular goal. After all, good creatures (namely, PCs) go to the lower planes to free captured loved ones, or fight some big evil nasty, or whatever. Perhaps some powerful evil group wants to go hollyphaunt-hunting, or wants to capture devas to get their spark. PCs would be called upon to foil such activity.
Conflict doesn't have to involve pain, violence, or death. It can just as easily be a peaceful dispute. I think everyone can agree that "good," while able to unite far more easily than "evil," is hardly monolithic. If it were, we wouldn't have a gamut running from Lawful Good to Chaotic Good. And even though some may dislike the alignment system, it can't be argued that most "good" people have different ideas of what true goodness is.
Even Elysium, the plane of rest, has some conflict in the "bad things happen for good reason" way. People on Elysium experience misfortune because the plane wants other people to spread the goodness. It rewards those that help and punishes those that defy it.
While evil creatures invading an Upper Plane makes for a good adventure. However, the intent I'm getting at here is attempting to create conflict that helps define the plane. It should be something inherent to the plane, something that makes it interesting as a standalone entity. If I read the plane's entry in the Planewalker's Handbook, I should be able to get a sense that there's really something going on in this plane and this place is worth having in my Multiverse. And while a place like Bytopia certainly has a unique concept, a "plane of hard work" is not terribly interesting. People are industrious and work hard all over the Multiverse; why should I care that Bytopia exists? What's there to make it more appealing than all the other places that do the same things? That's where a conflict comes in -- to liven it up and give it a persistent feature that makes it feel less tacked-on.
http://kaitou-kage.deviantart.com/ -- My deviantART gallery
http://www.planescapemetamorphosis.com/ -- Planescape: Metamorphosis, a Planescape webcomic in the works