If there is a conflict, then he is definately a POW. If there is no armed conflict, then this is yet one more reason why the Gaza blockade is Illegal. Whether a captured soldier is a POW or not does not depend on which side of the border he is on when he is captured. Even if one takes the position he is not a POW, his capture is no more illegal and immoral than Israel's continual arrest of Pals in illegally occupied territory and during their frequent incursions of Gaza.
UN experts: North Korea continues to evade UN sanctions (AP)
from the article: Carter: Hamas agrees to deliver new Gilad Shalit letter