A deal to release 450 Palestinian prisoners in exchange for Israeli soldier Gilad Shalit would be much more justifiable than the two deals with Hezbollah. Does that mean the current deal is a right move? No, it doesn't.
The deals with Hezbollah were so extremely wrong that it isn't hard to achieve a better agreement. We gave the Lebanese terrorist group hundreds of prisoners in exchange for soldiers' dead bodies and one living criminal. We should have only given dead bodies in exchange for dead soldiers, and the criminal, who was captured while doing something illegal, was not worth a high price.
Gilad Shalit is different. He is alive. It is right to release hundreds of living Palestinian prisoners for him. The question isn't the number. The question is who is being released exactly and how they will affect Israel's security. What these prisoners have done before is unimportant. It is important to assess what they might do if they are released. If they pose a serious threat and will carry out or plan attacks that will kill many Israelis they should not be released.
Also, Palestinians with Israeli citizenship should not be released as part of this deal. We cannot let Hamas become the representative of Palestinians inside Israel. These Israeli citizens who were involved in terrorism are not part of the Hamas's jurisdiction, or even the Palestinian Authority's. You know what? Any Israeli Arab prisoner who wants to be released as part of the Hamas deal should be given two options: either stay in prison till the end of your term, or give up your citizenship and be deported to Gaza. Who needs convicted terrorists walking Israel's streets?
So, should Israel go through with this deal? I don't know. I don't feel that I know enough about the prisoners Hamas is demanding. If the threat to Israeli civilians is low, than I support it. Otherwise, I don't.