According to Chris Chabot (Developer Advocate at Google), "We're only just starting down the road of the Google+ project, but we love our Google Apps users so please stay tuned"

[from comments on http://techcrunch.com/2011/06/28/google-plus/]

Google recently forced users to make their Profiles public, and announced that it was going to delete private Profiles. If Google+ requires a Profile, then count me out.

I found a workaround to bypass this error message: open anybody's profile and "switch accounts" from there. Details at http://codebistro.com/2011/07/09/google-oops-you-need-google...

Yeah, this is really annoying. My invite is stuck in limbo right now because it's tied to my Google Apps email address, which won't work with Google+.

yep. as we have buzz in several month http://googleenterprise.blogspot.com/2010/02/google-buzz-com... :)