The deal replaces the long-running "two for $5 mix-n-match" promotion but still let's you choose the Original Chicken Sandwich or Big Fish Sandwich (but not the Extra Long Cheeseburger) in addition to the Whopper, albeit at a higher price.
Depending on how it goes, two for $6 could be Burger King's new two for $5. Otherwise, they might switch back to the previous deal and pricing.
Photo via Burger King.