Oh, did this just launch today? That's funny, I thought I only noticed it today. In any case, I'm using it already. I was going to build SAML into this app that we have deployed on GCE, so that employees can access it over the internet as long as they're authenticated, but instead I put it behind an IAP, and our Google auth already talks to our SAML server, so Google is effectively doing the same work for us.