Roll back the Blockchain - deny the thief his spoils and return lost coins. Coin can recover.
Don't roll back the Blockchain - likely(not with 100% certainty) to deny the thief his spoils by watchdogging where the coins go and victims get nothing returned to them. Coin will definitely not recover.
You decide.
As much as I've been a supporter of VeriCoin... a fork to roll back the blockchain is a very tough pill to swallow. Have to say I'm with dadams.