Well with steam workshop downloading mods is very streamlined. What would be awesome is if you had some mods installed, and you were hosting a D&D game, anybody who joined your game would be prompted to automatically download and activate mods you have from steam workshop (or even more awesomely, they could connect to Nexus and download them automatically, but that's a lot to ask).
But something basic like automatically activating/deactivating your mods when joining a game would be a good start.
