The token would either have to work with a single-sign-on authority that would authenticate you to other parties (like OpenID, but hopefully easier to use), or

The token would either have to work with a single-sign-on authority that would authenticate you to other parties (like OpenID, but hopefully easier to use), or it would contain multiple "authentication slots" for the parties that issue credentials. Both things already exist today, although I don't think they are very widely deployed. But certainly companies that deploy something like the RSA tokens have a company-wide single sign in working with them, and there is no reason for that to stay within one company. Both solutions are technically very different from a password manager.