Phesoj,
If a plea deal with stop the three children and rest of the victim's family from having to go through a trial it might be worth it considering. The suffering a family goes through when it's another family member who committed the murder is really terrible. It is especially hard on the children no matter their ages. I know from my personal experience.  
He certainly deserves to be locked up for the rest of his life for murdering his wife. Since this is a federal prosecution it will be interesting to see how the court operates versus the state court.