IMHO He won't be there just his video's or PSA commercials on a 50 ft. screen.
This concert is about Not Texting and Driving and also to raise thousands for schools.
The good news is that we know that phoneguard is sponsoring it and they will bring the PHONEGUARD name in abundance.
I can't see starting a frenzy with Justin there when the reason for the concert is to raise awareness against texting and driving and to have it viewed to 8,000.00 schools and also on Pay pre-view to thousands more.