Yes, it's definitely geared towards the teens and the tweens. But the short (175 pages) novella was an interesting story, which added to the Eclipse experience. It's set from the perspective of Bree Tanner, a newborn vampire who was created with the purpose of attacking the Cullens and Bella, although she is not in on the plan. In the short time of her vampire life, she befriends a fellow vampire, Diego. Their relationship is cute and sweet, although short lived (as the title gives away).
For Twilight fans, it keeps the story going and is a good, easy summer read. I finished it in just three nights. On to the next one!