Especially if we create a LN god of natural order for the Mechanus issue, it could be cool to include an article on druids on the planes, especially tying in to Mechanus with druids who are also guvners. I made one up as an npc last week for my own game and, at least in my books, it's a pretty killer idea that I think might not occur to a lot of people.
Most gamers see mechanus as a cold, 'mechanical' place filled with constructs and artificial life, devoid of nature. And while it may not have the same kinds of nature as a prime world would, most of the planes don't. Planar druids don't need to be restricted to Arborea and The Beastlands. There can be druids on any plane, all of them contain features that are 'natural' to them.
What kind of crunch can we offer in an article like this? A new druid archetype for pathfinder Planar Druids that doesn't restrict the druid to prime ideas of natural? Planar 'animal' companions? New domain-like options for the Nature's Bond ability, similar to how Inquisitors got Inquisitions in UM?
New items, maybe?
First off, a planar druid should have a home plane and the powers they acquire should in some way reflect their home plane. Maybe opening up different sorts of shape shifting possibilities, animal companions or even swapping out powers for something that's themed for the plane in question. If you're wanting to sketch out the abilities of a planar druid, I'd suggest doing it one plane at a time. Since we're working on Mechanus stuff, we should strictly focus on developing a Mechanus druid rather than trying to develop a full-on planar druid. We could do it up in the style of Pathfinder's class archetypes.
I'd also say that a planar druid's alignment must match up in some way with their home plane. Mechanus - Lawful Neutral; Arcadia, Mt. Celestia and Bytopia - either lawful or good (Arcadia favoring lawful, and Bytopia favoring good); Elysium - Neutral Good. So forth and so on. An Outland's druid could have any neutral alignment.
Suggested changes for a Mechanus druid might be to drop natural animals for their companions and instead use gear spirits and moignos (living equations). Rather than going with animal forms for their wild shaping ability, make it constructs. Bonus language would be Modron, rather than Sylvan. I'd have to spend more time working out the specifics, but it would run more along those lines.