I think if people would use BTC marketplaces with easy access in future, this will not be such a big problem. They only need to open a new account at a payment processing service they didn´t use before, and then start trading with other people on a marketplace for BTC. These payment processing sites will not be able to cancel all accounts. If it happens, then trade with another. Well, some kind of reputation system would be helpfull.
I made a list of payment processing service here: http://bitcointalk.org/index.php?topic=7069.0
I try to sort them and start a discussion what are pros and cons of them. Maybe we find ways which can´t be blocked. For e.g. selling scans of Ukash and cashing out with a debit.