Earlier quoted context omitted.
It would indeed stabilize Bitcoin, but I don't see what's so ironic about it. Short-selling and other derivatives substantially stabilize a lot of markets, popular delusion to the contrary notwithstanding.
But now there is double the incentive to artificially drop the value of BitCoin as much as possible, no? I don't know how trading bitcoins work, but won't this increase volatility both ways in addition to overal stability (taken as an average).
What Bitcoin really needs to smooth out its volatility, as far as I can tell, is HFT market-makers trading tiny amounts of BTC by the millisecond. Which should theoretically be easier with an all-digital currency--but, if done in "real" BTC, requires probably at least a million times the block-chain growth velocity Bitcoin currently has. It could still probably be done with "BTC liabilities" on a private exchange, though.