Signing in to Ubuntu with Ubuntu One credentials

Allowing people to sign in to an Ubuntu installation with their Ubuntu One credentials has a number of benefits: it makes sense on smaller or attached devices, your device is automatically paired with Ubuntu One, meaning that you have all your data without an additional "pairing" step, it means that you don't have to remember a different password per machine (not necessarily a benefit in everyone's eyes). This session is to discuss how, technically, signing in to an Ubuntu installation with Ubuntu One credentials might be done, what it would mean (does a new "local" user account get created? Should the "local" user account already exist and be matched somehow with the U1 account?), and which issues are generated by it (local caching of credentials, logging in while offline, etc).