Here's an early good sample of what to expect. Dirty Weasel interviews mod creator Zealotlee. Zealotlee is actually making some anticipated advance work for FO4. The video will show very raw concepts of his mod that can supposedly be ported. Quite interesting as he even already made his weapon mod to be "modular", just like what's shown in the trailers. FO4 was also mentioned to be using Skyrim's game engine (albeit more tweaked & more polished), therefore, it's probably safe to say that any anticipated work can be based off that.