Google ID as sort of the IDP?

[Oleg Chaikovsky]

I have seen the large amounts of information about connecting Google 
Apps via Shib which is fairly straightforward at this point. Google Apps 
as an SP.

So - now - if a group wanted to make their Google Apps domain to be the 
primary identifier for all of their other apps - would that simply be 
using external auth through the IdP? Simple as that? I keep thinking 
there must be more to it but all info I have read on the Wiki points to 
that model. (there are no additional attributes to consider in this idea).

-- 
Oleg Chaikovsky