To my understanding this is a fundraiser for Special Operations Warrior Foundation. They are a legitimate group that actually does a great deal of good for former troops and their families.
http://www.specialops.org/?page=AbouttheFoundation
I fear Beck's biggest piece of media "hocus pocus" will be in "look how the left wing reacted to me when all I was doing was raising funds". He intentionally did not mention what his agenda or platform for this rally is ( in the article ALH posted). I think perhaps he has no intention of discussing politics, rather to allow all the conjecture make vocal adversaries appear to be jumping the gun or at least, jumping to conclusions.
Not a fan of Beck. Not a fan of Sharpton either.