Ok, fair point. It does promote adaption of the currency.
But when it's done at the expense of 'real' withdrawal methods it's strange to say the least.
You are effectively limited to some prepaid credit card, and dwolla, if you actually want to cash out.
True, I'm not sure why they offered normal methods of withdrawal at first and now they're all gone. The only thing I can think of is that they received far more attention than they expected and couldn't get everything working properly right from the start. Remember, TradeHill has only been open a few days so far -- they don't even have a working market data API yet. I'm sure the bank transfer withdrawal option will be back soon.