they are returning the characters to the "heroic" atittude that started it all.  it dosent necessairily have to be lighter or heavier if you will, because like i stated before its more about the stitude than anything else.  If you move things back to the way they were, in a sence there really wasnt a whole lot of light (considering the powers they all had supers especially) but their atitude was more carefree and ..well i guess they also werent that serious and troubled.