In simple terms, this technique allows a series of trustless off chain bets on a single payment channel. Each node can thus maintain "bet channels" like "payment channels" with a number of partners, and bet against the partners on anything from exchange rates to sports to politics to you name it. By hedging bets with one partner against another partner, much like banks do today with OTC derivatives, you can create a decentralized "bet exchange" with no counterparty risk. I'll write up the implementation details in a Technical Discussion thread next week.

Simply put, this will let people and companies hedge the dollar value of their Bitcoin holdings without having to trust their money to an exchange that can get shut down by a government, get hacked, or run away with customer deposits.

Edit: I agree with your list. I also disagree that this is any more complex than what Satoshi has done.