The deal commemorates the over $5 million raised from sales of the drink for youth organizations in the US and Canada. Starbucks donates 25 cents per cup sold of the Oprah Cinnamon Chai Latte to support youth education and will be donating 25 cents for each free cup given during the promotion as well.
The drink goes for about $4.25 for a 16-oz Grande. I tried it last year when it was just the "Teavana Oprah Chai Latte," and you can find the review here.