Simply giving to Hamas demands can potentially open up a can of worms wrt the security of every other soldier in the region. This also has the potential for other militant groups in the region to simply try and resort to only kidnapping IDF troops. Shalit should come home but Israel cannot bend over and expose itself to future attacks of a similar nature. There has to be provisions put in place.
Report: Iran's Culture Ministry refuses to allow Barenboim to perform in Tehran (DPA)
from the article: Report: Shalit mediator calls for urgent international action