From Skip Willams on the Wizards site Death of a Master: If the master dies, and the familiar survives, it loses all abilities associated with being a familiar (as if it had been dismissed). As a house rule, you might want to delay the familiar's loss of abilities for a short time, say one day per level of the master.If the master is later brought back from the dead, the familiar has whatever abilities that go along with the master's new level. http://www.wizards.com/default.asp?x=dnd/rg/20050927a I am personally in favor of house ruling this as suggested perhaps even a longer time to allow a familiar to try to bring her master back.
The familiars are sent to an island "Village" and kept there against their will. The are no longer addressed by their given names but have a number designation instead.