According to this Reuters report, Fallout fans aren't going to have to wait another decade to get involved with another instalment in the series.
From the piece:
Gamers have been waiting 10 years for Bethesda Softworks' "Fallout 3," for PC, Xbox 360 and PlayStation 3.
"I think it's good for people to miss things," said Todd Howard, executive producer of the game. "Ten years between 'Fallout' is a bit long, but I think there's this nostalgia factor."
Fans of the post-Apocalyptic game, set in Washington, D.C., won't have to wait another decade for "Fallout 4." Howard said he believes three years is a good time frame between games.
More through the link.