Both Hammas and Iran are IMHO just symptoms of the great clash arising between the Western and Muslim cultures, as are the riots against Danish caricatures (If we Israelis demonstrated against every anti-Semitic caricature in an Arab newspaper we'd never have time for sailing ) and the riots in France a few months ago.
While the U.S. has finally realized the strategic danger and taken action, most of Europe is still reluctant to admit a problem exists, and must be tackled seriously. This is not to say that only a military solution exists, quite the contrary, only to point out that sticking ones head in the sand will probably not work.
As for Hammas, whilst definitely a setback for peace prospects in our volatile neighborhood, I don't believe anyone knows where we're going so early in the game. Optimistically, they may turn out to be better situated, coming from extreme ideology, to take the painful steps required for peace - After all, two of our tougher leaders, Begin and Sharon, gave up more than others. More realistically, we’ll continue battling it out militarily, economically and politically for a few more rounds .
Iran is a significantly more dangerous threat, regionally and globally. Once an advanced, almost Western country, they now lead the radical Muslim world in its fight against much that we hold dear - freedom, equality, and democracy. Armed with nuclear weapons and the will to use them, and joined by radical Muslims the world over, Iran endangers much more than Israel and Middle East stability.
Most Israelis are closely following the growing (albeit slowly) international efforts to stop Iran, hopefully before we reach a nuclear standoff, which would probably not end as peacefully as the cold war did.