A new feature in 3ds max 2012 is Substance procedural textures.
Are there any good online libraries or resources for substance maps?
Currently, Allegorithmic restricts who can publish Substances, so you can only get them from their sales points. TurboSquid Substances, Allegorithmic.com, and Unity's Asset Store.
They have signalled that they are reviewing this policy.
My personal opinion is that until they do, they have no hope of competing with FilterForge's business model (which encourages an ever-growing library of free filters, increasing the attractiveness of their product).