Google apps supports openid for hosted domains, but requires some extra extensions to the standard openid protocol. Our company is moving to google apps, and we'd like to use openid for Bitbucket authentication.
Currently if we enter the openid URL: https://www.google.com/accounts/o8/site-xrds?hd=example.com
Bitbucket returns a 404 response received error. But if you try the same URL with an example OpenId implementation like http://www.puffypoodles.com/ it works as expected.