Despite extraordinary interest in this story - every event makes headlines around the world - no evidence has been presented that would justify the charge of 2nd degree murder, that being the case there were justifiable legal grounds for arresting Zimmerman on that charge. This was just political grandstanding by the prosecutor, and there is no doubt that before the trial begins manslaughter will be offered to the jury as an option.
Actually, you may be surprised to find I agree that manslaughter may have been the right charge to bring against Zimmerman here. Unless there's some indication of forethought that hasn't come out yet, I don't think the Murder 1 or Murder 2 is the right charge... again, unless there's something we haven't seen.
As far as the impact on the rest of Zimmerman's life? It's better for him to go to trial now. If he's not charged at all he becomes the face of racism for a generation. Going to trial let's him have the chance to air all the facts and clear his name. After that, it's up to him to rebuild his reputation.
If that sounds callous, again Zimmerman choose to follow that kid even after he'd called the police. He was't trained to handle that situation, made a poor choice, and now an unarmed kid is dead. It's possible Zimmerman acted in self defense, but if I'm unsympathetic, it's because he put himself into that situation.