Guess you could move them into bitparking and trust doublec's monitoring and check point lock in.
Don't keep them in bitparking. It'll be shutting down all namecoin transactions in a few days or block 19000, whichever comes first. If the attack succeeds all namecoins will be considered lost, the exchange will be closed permanently. If it fails the exchange will reopen for withdrawals. If the network hits 19,200 and there is a reasonable hash rate going then I'll consider reopening trades.