hello, I did it, arbitrage bitstamp to mtgox or better : btc-e to mtgox.
The problem is when you want to withdraw from mtgox.
I tried a USD withdrawal by SWIFT transfer, and 2 months later, still nothing, so I cancelled my withdrawal.
I tried in EUR by SEPA (only 1000 EUR by day and 10,000 per month), and it takes a long time (from 1 to 2 months) but it works.
But I don't do it anaymore, it's still too long to be usefull.
MTgox said it will improve its SEPA delay, but When I don't know !!!!