The official site's been updated with some new concept art. This one is reminiscent of the Fallout 2 tanker (just like the music kind of is). I'll leave it to someone who knows how to use the gallery to upload the image there :)
It's the best of the lot so far, in my opinion at least, though I'm still waiting to see something specifically Fallout. Also, I'm waiting to see a living creature. If it's anything like a mudcrab, well, it's ON.
Edit by King of Creation: Here it is
It kind of reminds me of New York City and the Intrepid.
Thanks to LoneGunman for the tip.