OpenID, Facebook, & Twitter don't provide a users email. (OpenID might - but you still have to verify it's legit). SwiftLogin just off-loads the email verification for you (and in turn, every site after you) so that you can just let them in right away.
How is that any different from what OpenID offers?
Actually, that's not really possible because most people who do this chose simple passwords under 8 characters. SwiftLogin requires much more complex passwords to even create an account.
smart idea - how's early traction with app producers?
however this doesn't allow for social integration and ideally one email/pass to rule them all is the facebook motto.
It's also the OpenID motto. That is the whole point of SSO. You can also use multiple emails if you want multiple accounts.