BankSimple sound interesting but they will have to be offering something really awesome for me to even remotely consider doing business with a commercial bank ever again. (There days, I only deal with credit unions.)
BankSimple, not being terribly large, can't force the incumbents to play their game (like say, Apple could with AT&T to some degree - and they got lucky getting in with Cingular).
It will be interesting to see how this fares when the "financial service" supplier(s) starts yanking the chain.
And if they do have their chains yanked, they can switch their provider. It's not like banks have "coverage" to lock you in, like mobile networks.