MediaWeek reports that

Fox will produce original episodes of it's resurrected hit Family Guy exclusively for the Web sometime next year.
...
While a specific distribution model was not discussed, Levinsohn implied that these episodes will be sold directly to users. Speaking hypothetically, he spoke of selling episodes of the series on an individual user's MySpace profile for a $1.99 an episode after these users have made an initial purchase.

I'll definitely be interested in finding out more about this...