Hershey recently won a reversal of a USPTO refusal of its product configuration trademark application for it chocolate bar configuration (see below).
x-ref: In re Hershey Chocolate and Confectionary Corporation, Serial No. 77809223 (June 28, 2012) [not precedential].
This reversal was comprehensively discussed by our colleague, John L. Welch, on his TTABlog today, at the following link:
Have a look at the Trader Joe's Chocolate bar configuration, however, and you will see it has the same rectangular configuration, including the same 3 x 4 design (see below).