Possible Clues:

• Rival of Coke
• Pop icon?
• Brad's Drink, nowadays
• Soft drink that started out as 'Brad's Drink'
• Brand whose ads once featured Michael Jackson
• Soft drink that started out as "Brad's Drink"
• "For those who think young" soft drink
• Mountain Dew producer, informally
• Big name in pop
• Rival of 25-across