I remember there was a post about Eric Gordon not being on the USA Select Team, but on Ralph Lawler's latest blog post he mentions EJ and Blake Griffin remaining in Las Vegas after the summer league to train with the team.
Here's the link: http://www.nba.com/clippers/features/lawlerslaw.html
I'm guessing he was a late addition, but was it because somebody declined? Still, he should have been included in the original roster. Hopefully he'll get more recognition now.