What are the PC requirements for fallout 4 ? Minimum, average, optimal?

We won't know until October. They estimated 3-5 weeks before the release on Nov 10th.

I really seriously doubt they will give the requirements out until the very last minute..

I would guess that if you could play Skyrim with the HD DLC added you shouldn't have a problem, though what's needed to allow 'Ultra' settings we won't know for a while.

I don't think you can assume that. In the screenshots I see better lighting, draw distance, textures and models. Who knows how much extra performance that will cost?

But most of the time the official 'system requirements' are useless. They don't tell you the settings and framerate they're for.

My guess is Beth will go for 30fps @1080p on both consoles. The XB1/PS4 perform similar to a Radeon 7770/7850. So double that if you want 60fps and you'll need something like a R9 280X or GTX 770.

The big question is VRAM requirements. Skyrim can be very memory hungry with HR texture packs. The official HD-texture pack replaced some of the textures and still required 1GB, but it only ran smoothly on 2GB cards. For Fallout 4 I estimate 2GB minimum, 3GB recommended.