Israel has few victim cards to play before world opinion and Shalit is one of them. From a PR point of view, a Shalit release is bad news. It would close that file and deprive israeli of good hasbara. all the while over 10,000 Palestinians, including women and children, remain as hostages in Israel.
Knesset passes 'Norwegian Law' allowing ministers to resign their seats, remain in cabinet (Haaretz)
from the article: Gilad Shalit must be released at any cost