Additionally, they've added a new Hot White Chocolate and White Chocolate Latte.
Since the drinks are all various combinations of steamed milk and white chocolate syrup, plus whipped cream and/or espresso (depending on the drink), it basically just the return of white chocolate-flavored syrup at participating McDonald's restaurants.
The "new" White Chocolate Latte is just a White Chocolate Mocha without the whipped cream (i.e. it's espresso, white chocolate-flavored syrup, and steamed milk), while the new Hot White Chocolate is a White Chocolate Mocha minus the espresso (i.e. steamed milk, white chocolate-flavored syrup, and whipped cream).