Back in the 90's on the cypherpunks mailing list, Wei Dai (of Crypto++ and b-money fame) invented a system of anonymous lending.
That's an interesting system, but it seems rather academic (that said, I once thought the same of BitCoin yet here we are).
Leg-breaking is I'm sure very satisfying, but ultimately you're still out of pocket. A key part of lending is assessing the credit-worthiness of the borrower to try and minimize the amount of leg-breaking required. With complex lending you may have to consider all details of their business scheme to decide "is it good or is it wack?". That isn't possible under Wei Das design.
The problem it solves is also obscure. It is a complicated way of making or receiving anonymous loans between non-anonymous participants. But that's exactly the same model of privacy already used in the real world. If I take out a loan from my bank, only they and I know about it. I didn't need any Pot to disguise that. The built-in privacy of the financial system (or BitCoin) is good enough. The scheme isn't useful for some kind of cypherpunk crypto-anarchy either, as all participants need to be strongly identified not only between loaner and loanee like today, but to everyone!
Finally, the system distributes responsibility, which is the opposite of what the legal system requires to go after somebody. In a Pot system, when somebody doesn't repay it's clear who is at fault, but not who should take the trouble to go after them.
Daniels page appears to be a subtle advert for Ripple, not that there's anything wrong with that. Ripple is kind of the opposite of anonymous lending in that people are all too painfully aware of who is in default ... because it's their own friends who may transitively owe them on the behalf of other people!
BitCoin doesn't seem to have much to say on the topic of credit. Whilst you can do some clever things with the scripting system, credit is ultimately about people and the trust between them - not something that can be easily encoded into a protocol.