If you liked Avatar (or Harry Potter for that matter), you'll like this book.
A very fun story, and one with many surprises. I was totally drawn in by the end of the first chapter, and I could not put the book down until I finished it. The author tells a good story of once-passionate lovers who meet again and find themselves on opposite sides of an emerging conflict - a conflict that could change the future of mankind. I especially liked how he would switch perspectives from chapter-to-chapter, first telling the story from his perspective, and then later advancing the storyline from hers; each chapter fleshing out their personalities more and more until you really get a sense of each person.