Speaking with PC Power Play, Bethesda's VP of PR and marketing Pete Hines talked about Fallout 4's lightning and "bright" visuals compared to Fallout 3's more bleak and grey image. He said:
"The team was very self-aware that Fallout 3 was a depressing-looking world, but that was part of the motif that they were going for, which is, you emerge into this world having lived in the vault and it was very much, your father is on this quest to save humanity. Like, humanity needs saving. Look at all this. It’s horrible. Somebody has got to do something. This has got a slightly different tone to it. And not specific to the story, but just, the mood of the world is more of a, this is life, like, this is normal. This is reality now. There is no more nicely manicured lawns or white picket fences or going back to that. This is what home looks like now."
Nintendo is selling their IPs to Microsoft and this is true because:
http://gamrconnect.vgchartz.com/thread.php?id=221391&page=1
