Hmm, I thought this kind of scheme might be useful in providing a small number of authentication "tokens" (possibly down to one) for reuse across many systems -- but without some of the downsides of existing systems which claim to provide a sort of single-sign-on system.
Yes - it is like that.
But for mouser to go and implement it as an additional authentication mechanism probably is too much work. The current one here works already.
That system is a more robust and secure, but it's not the kind of thing that people normally use, so there's a learning curve for it. It's probably not worthwhile for "normal" sites (e.g. forums, etc.) to use quite yet. If it becomes widely adopted in other areas, then it might make sense for "normal" sites to use it.
In my own experience, SSO is horribly broken. I want to tear my eyeballs out and ram broken glass bottles through my eye-sockets whenever I even think of SSO. That would be less painful.