That would be a hoot.
DM: You see a lich.
Cleric: I cast ressurection!
DM: Lich is ressurected back into a human wizard.
Former Lich: "Doh! I spent 180k on becoming a lich, not to mention that my minions won't recognize me now. DOH! Stupid ressurection spells, this is the 4th time this has...