I'm looking forward to when their LDAP adapter [1] is ready for prime-time so that we can use it internally for our own email addresses. I'm curious if the GMail adapter would work if you host your company email at google?
We're using Vinz Clortho in production right now (try to log in as callahad@mozilla.com and you'll be prompted for my LDAP password).
It's not super generalizable, but if you're interested in rolling it out on your end, ping our mailing list (https://lists.mozilla.org/listinfo/dev-identity) and we're happy to support you while you get that going.
A generic Google Apps bridge is somewhat tricky, but we're really interested in prototyping it over the next few months.
As callahad pointed out, it's already in use for some Mozilla sites, and I at least haven't seen any problems with it. In fact, I just logged into one (with my Mozilla LDAP credentials) earlier today :)
[1] https://github.com/mozilla/vinz-clortho/