There's some buzz going around about a potential Fallout 4 being announced in early December.
http://thesurvivor2299.com/
Right now, the site is just a date and some morse code with the Fallout font and the Vault-Tec logo.
Someone did a breakdown of an audio file that was apparently pulled from the domain, too. It has another Ink Spots song (To Each His Own), like the other Fallout games have had (Maybe and I Don't Want To Set The World On Fire) among some crashing waves and the sound of a gun being loaded. At this point, nobody's sure whether or not it's legit or if it's a hoax.
Hopefully it's real. . .the Fallout series is probably #2 on my list of favorite video game series of this generation (behind Mass Effect). Maybe Bethesda will even hire some testers to find most of the bugs before the game comes out this time around.