No need for a *massive* short position, you can allow many people to take out short positions in the same currency and collectively they form the short position and are the 'creators'.
If you have a problem with the margin-call, the least you can do is enlighten me to return the favor.
I don't doubt that you have it working for BitShares, but the mechanism for lining up more short positions to replace people who are forced to close their positions is fuzzy to me. What if not enough people want to short? I'm just not convinced that the longs balance the shorts over the long term.
Ugh, I fear what Pandora's box I might be opening by bringing this up. We may have to move to a different thread if this goes more than a couple posts!
Also, I'm going offline now. For reals

Talk to you guys tomorrow.
If there exists demand for BitGold then the price will be bid up based upon the current supply. At some point the price is above market value and anyone could make money by shorting it. BitGold has potential to go above market value in 2 ways: 1 as a result of a short squeeze & 2 due to higher demand for BitGold relative to the supply. The theory is that if there is easy money to be made (price above parity) then someone will short it until it reaches parity.