Step 1: "Phantom BTC" credits
Create a new, fake currency called "Phantom BTC", which cannot be deposited nor withdrawn.  Credit all users with Phantom BTC equivalent to their current outstanding BTC holdings and set BTC holdings to 0.  Future BTC deposits will be credited as BTC.

Step 2: BTC to Phantom BTC exchange
Create a new trading pair between BTC and Phantom BTC.  Collect a Phantom BTC commission on every trade.  This means that on every trade the amount of Phantom BTC in existence will decrease.

Step 3: Phantom BTC buyback
Use profits from other trading pairs to buy back Phantom BTC, further accelerating the rate at which it disappears.  If the stolen funds are recovered, all of the Phantom BTC can immediately be bought back.  Eventually there will be no more Phantom BTC and Cryptsy can close that trading pair.

Having a BTC to Phantom BTC exchange will allow pessimistic bagholders to withdraw their BTC at a loss, while allowing opportunistic traders to essentially buy Cryptsy's debt, with the possibility of significant returns when Cryptsy finally gets everything back on track.  Patient/optimistic bagholders can simply wait until a favorable exchange rate or until the buyback.