I really love this feature in MW3. It should come back to Black Ops 2 Multiplayer to be able to show off your previous prestiges. People can also use this feature to see if the play had any experience in the past cod games or to see if MW3 or Black Ops 2 is their first Cod game.
Cod 4 10th
Cod W@W 10th
Multiple threads on this very issue, use your search tool sir.