"We've got plans for Fable 3, 4 and 5 actually,"As Joystiq points out, since it took Fable three years to develop, the most likely dates you can see the next installments of Fable would be 2011, 2014 and 2017.
"It's a big story arc and if you play Fable II you'll recognize things from Fable 1."
Molyneux also hinted that Lionhead studios isn't just working on Fable projects but a secret project. The only hint he gave was this vague sentence:
"[the] kind of the result of an experiment that went incredibly well."You can check out the rest of the interview for yourself on the video above.