Yes, I've learn't my lesson, requested withdrawal from Mtgox in July (when bitcoins were just over $100, finally gave up, requested they refund so I can exchange it back into bitcoins again, only thing is it took them 4 days to process my request, during which bitcoins went from $200 to over $300. Arbitrage, in Mtgox is the stupidest idea ever if you're outside of Japan.
Arbitrage opportunity for CNY is better, as I'm currently conducting AUD -> BTC -> CNY arbitrage via our managed fund (
http://bitcoinsreserve.com/)
And am looking for partner to conduct USD -> BTC -> CNY.
PM me if you are trading in USD and have a bitstamp/btc-e account and wish to explore this further.