"This new concept will only be around for a short time,"  William White, group brand director for Diet Coke and Coke Zero at Coca-Cola North America, told Adweek exactly a year ago—when a new Diet Coke can design from San Francisco design shop Turner Duckworth was first unveiled for a limited fall run. Well, it looks like that design, featuring the big D and little (though even bigger!) k, was a huge hit—so much so that the company now says it will become the permanent Diet Coke can design,  beginning Sept. 1. For now, the existing design remains on Facebook and elsewhere—grab your commemorative cans while you can. Meanwhile, in other Diet Coke news, the brand is down to 10 finalists in its Young Designer Challenge, which asked budding fashionistas for T-shirt designs—with AdAge reporting that Gustavo Alonso's design (see below), featuring the new logo, will be sold in Target stores nationwide this fall.