Just here to share my personal experience, as Arbitrage does work as I have moved coins to BTCChina from Gox, stamp and btce.
How do you get your money out of China?
Pretty straight forward, international USD wire to your designated bank account after arbitrage (BTC -> CNY -> USD) has been completed with the bitcoins provided.
Keeping in mind that Arbitrage generates a % ROI week on week depending on spread, and sometimes under performs the appreciation of bitcoin value, but it at least is a bit more of a sure thing, and as it has a different risk profile, is a great way for you to hedge and increase your government backed currency.
Cheers,
Sam