From what I understand, the Developer Marketplace was something that Multiverse was going to set up, but it would seem that this in fact never happened. There is a page on the website for it, but that's pretty much.
One of the things I am proposing we do, once the platform goes Open Source, is to create our own Developer Marketplace (codenamed The Bazaar, perhaps?).
Developers could host their own models, textures, sounds and code snippets on there, for the benefit of other players. They could choose whether to list it as a freebie, or they could put a price tag on it, which will be determined by the developer.
A very small portion of the sale price (maybe 5-10%) could go towards the 'Multiverse Foundation', which will in turn be a source of money for paying website hosting fees. (This is something we can go into later on)
So, the idea is to have something similar to the Leadwerks Engine's Asset Store, where it is based entirely on Multiverse, with all the models in the correct formats (.DAE with the texture file, or .MESH with the material file), optimised images, clear and coherent code snippets and modules, and so on and so forth.