Byzantine-Once we get a decent and balanced system playtested, I'll finalize details on Allomancy's in-world support. We can figure out a way to pull this off really smoothly, I can tell. I'm tempted to make it a dwarf thing, but I know that they aren't the Tolkienian miners of every other setting, so it doesn't make much sense. Logically, it makes sense for Allomancy to be centered in areas with mines and other sources of metals, but I haven't really decided where that is yet. Llanca has some (one city in the Dotze Affariata), but that's about it. Oh well.
Now, the question turns to what support there should be for other subsystems. Psionics are a tentative yes, but I'd still like Eldest and Arathnos to weigh in on this. ToB stuff is in to whatever degree the DM sees fit, including a growing whitelist of homebrewed disciplines (if you know of a good one, hook a worldbuilda up. I might already have checked it out, but maybe not).
There's some other systems that beg my attention, however. Incarnum is one. It's decently balanced, I guess. Totemist is pure Urgal, and the Lightwood Rangers probably have a couple among them. I suppose the eight-armed beasts are in. Soulborn....I like substantially less. Without any gods (real ones, anyway) or paladins, their whole shtick has no tree to grow off of. Incarnates are in the same boat. Without objective morality to base the entire concept behind the class off of, they're without a paddle. I think I have at least four awful metaphors in that paragraph.
RE: Binders: See the seven levels of vestiges I've done, and get back to me. (Protip: They're in.)
Truenamers hold a special place in my heart. I think the fluff is pretty decent, and I love them like I love adopting puppies who were born without any limbs. They're cute, but can't really do a whole lot. If someone wants to play one, sure. I'll even let the Owl Clan and some Dotze Affariata university be their Paragnostic Assembly.
I think that's all. Feel free to weigh in.