Someone from Cryptic calling themselves IronAngel has posted on the Champions Online website today that the release date has changed

The original launch date was July 14th but has been pushed back to September 1st.

Bill Roper,the Design Director and Executive Producer was quoted "“It is critically important for an MMO to be as good as it possibly can be at launch. Through our constant dialogue with our vocal and supportive community of beta testers, we quickly realized that in order to implement certain features that we all considered important the development of Champions Online would require more time.  So that’s what we’re going to give it. Cryptic has a proven track record of releasing solid games and we want to maintain that with Champions Online.”

They say they are giving themselves more beta playing time so they can give a better, more polished game at launch.