Wiping out Hamas and subduing the Gaza Strip is not going to be easy for the Israelis. From Larry Johnson at sonar21.com:

The Gaza Strip is the home base of Hamas, but there is not a single specific location in Gaza that can be targeted and destroyed in order to bring an end to Hamas. I believe that Israel is dangerously over confident in its bellicose declarations that it will wipe Hamas off the face of the earth. Short of using nukes, Israel will have to send its ground forces into the strip and fight house to house battles. I think many of Israel’s supporters labor under the delusions that Gaza is a small area that can be easily dealt with. It is not.
Let me put this into perspective. The Gaza Strip is 141 square miles in size. Let’s compare it to Iwo Jima — that tiny island is almost 9 square miles. Unlike Iwo Jima — a small island — the Gaza Strip borders Egypt, which means it has a supply route that Israel cannot close unless Israel decides to go to war with Egypt as well. Why do I bring up Iwo Jima? Because the Gaza Strip is ripe with tunnels and bunkers designed to protect Hamas fighters from aerial bombardment. Just as the United States Navy decimated the surface of Iwo Jima, Israel can flatten the dwellings and office buildings crowded into Gaza. But the U.S. Navy failed to destroy the Japanese force hiding below the surface with the naval fusillade. The U.S. Marine Corps had to land on the beaches and fight a bloody month long battle to clear the island.