The MySpace message is rather amateurish, but the Revolution Money Exchange appears to be a limited bank account that hopes to do what PayPal does. There are severe limits, though.

(1) You link it to a regular bank account in the USA, which obviously raised John's security concerns.
(2) It is itself a bank account through a regular bank.
(3) It pays 0% interest (as you are probably aware, your deposits earn interest for the bank, so this is clearly where they hope to make some money)
(4) You can only transfer money to another account holder with them, or to your own linked bank account. This is how they hope to induce others to join and place deposits in the 0% interest accounts.
(5) they offer $25 to open an account, which isn't too unusual for new programs like this (ING direct has offered $25 bonus for opening a new account, and PayPal has offered incentives from time to time)

Without widespread participation, this system wouldn't provide much benefit to most people. And because it appears to be limited to Americans who can open a new bank account with this company, it lacks the universal appeal that PayPal provides.

As time goes on, I'd be interested in how others have benefited from such an account. I, however, will decline.