Is it too good to be true? Apparently not.
Sales of dark chocolate are up almost 50% over last year in view of the numerous reported health benefits:
(1) Moderate consumption can improve cardiovascular performance
(2) Improvements were detected in cognitive performance in several independent studies, including one funded by Mars, Inc.
(3) For performance athletes, chocolate milk comes close to the ideal food, replacing spent electrolytes and powering muscular performance with a synthesis of protein and sugars
Chocolate and Weight: Keep in mind that the known rules about calories apply - don't exceed what is normal for your age and activity level to stay svelte.
Some relevant reporting:
Health benefits of Dark Chocolate, Chocolate Milk, Cognitive Enhancement by Chocolate