If it's halted another 3 months (which I think is unlikely) then it becomes a very expensive trade for the shorts. Let's say someone shorted 10,000 shares at $15/share on 01/01/2011 for a borrow of $150,000. Let's also say that the annual borrow rate was 50% and the shares were borrowed for 6 months. That would be an interest expense of $37,500 or almost 4 bucks a share. They may still make money but it won't be nearly as lucrative as originally hoped for......btw, these are hypothetical numbers here as the borrow rate may be higher or lower, I don't know what the pps was on 01/01/2011, etc.
Given a long halt, their brokers may also initiate forced buy-ins when trading resumes and who knows what the cover price will be. This is especially true if CME gets through a forensic audit resulting ultimately in the filing of a clean 10K. The plot thickens....and, of course, the entire discussion could become moot depending on what happens over the next 24-36 hours.