So, one idea came to mind, what of a crafting profession that just produced unbound crafted blanks in a very wide variety of materials...
The current list of materials in the game are:
Basic (default), Mithral, Darkweave, Darkleaf, Adamantine, Flametouched Iron, Darkwood, Densewood, Dyeshk, Cold Iron, Alchemical Silver, and Greensteel.
To not completely outshine the raid Greensteel items (if that's even possible), there would need to be a lesser variant, that ONLY gave the greensteel item properties damage, but not the +5 enhancement bonus, and only use the greensteel item properties for weapons. To avoid confusion, this material should be called Lesser Greensteel. Also, Lesser Greensteel would make for an excellent high level carrot.
Rifling through the 3.5 DMG, Dragonhide armor can be added to the list. I can't comment about the 3.5 Ebberron campaign setting, I don't have that book XD
If Turbine's willing to pull info from the Arms and Equipment Guide (D&D 3.0, ISBN: 9780786926497), there are even more materials to choose from.
There's enough substance here to create two more grinds, armor and weapons, giving crafting even MORE options.
Also, at high levels, the crafters could have an option to take a blank and loose the binding restriction on it, from BtC, to BtA, or even unbound.
So, thoughts?