Capitalism has a way of weeding out bad ideas. I say go for it and see if there is interest.
FYI for that use case, most companies (mine included) use SAML (http://en.wikipedia.org/wiki/Security_Assertion_Markup_Langu...)
In specific, we use SAML to have our internal AAA LDAP infrastructure validate logins for a few cloud services such as workday and attask.
Might be worth looking at saas (saml as a service :D) as well.
Edit: This company does SSO with SAML 100% and they support pretty much all of the big apps you'd expect. http://www.onelogin.com/partners/partner-up/