OK, so there is not a final agreement, and we do not know all the details. But I think in the face of various individuals and groups screaming that Obama is Neville Chamberlain and so on, let me note a few things that I do not see many out there stating. I shall stay away from the reported details of the agreement other than to note that some commentators think that it gets more out of Iran in terms of concessions than many thought was possible in terms of limiting its nuclear weapons capability.
1) For about the umpteenth time, not only is Iran a party to the Nuclear Non-Proliferation Treaty, its supreme leader and commander-in-chief, Vilayat-e-faqih ("Supreme Jurisprudent") Ali Khamenei, has issued fatwas against Muslims owning nuclear weapons. It must be admitted that these were only issued after Iran stopped having a nuclear weapons program when the US invaded Iraq (one of the few good things to come out of that invasion), a program that had started under the Shah with US support at the time.
2) Given that he is a major religious leader, I do not think Khamenei is lying when he issues these fatwas. He really means it. If there is a danger, it is that a successor to him might undo those fatwas. But I view that as more likely if there is no agreement with Iran on these matters that provides them with economic and other benefits, as so many seem to want. In any case, I think as long as he is in power, there will be no further active nuclear weapons program in Iran with or without this agreement, even if Iran did once had one and remains somewhat unwilling to fully disclose what went on with it (the main area that Iran has still been secretive about).
3) While many outsiders continue to be thoroughly convinced that Iran is deadset on acquiring a nuclear weapon as fast as possible, this is not supported by the population. I do not have a recent poll, but one in October 2013 by a Gallup poll (sorry, link to it not working but can be tracked down by google) found that while 34% supported getting a nuclear weapon, 41% opposed that, even as 56% support Iran having a civilian nuclear energy program. And, while democracy is somewhat limited in Iran, it is not completely nonexistent, and the current president, Rouhani's election reflects these sentiments pretty well, and I think that even the theorcratic leaders like Khamenei do not want to get too far away from popular opinion (and Khamenei has already forbidden nuclear weapons anyway, as noted above).
4) While Netanyahu and his cabinet, along with a lot of US politicians, have roundly and fiercely denounced this agreement as threatening the existence of Israel, it has long been the case that both the entire US intelligence establishment as reported in official National Intelligence Estimates, as well as most of the Israeli military intelligence establishment, agree that Iran is not in fact currently actively pursuing nuclear weapons. It has also been the case that many former Israeli intel people have openly criticized Netanyahu on this issue, even accusing him of lying, and some supporting this agreement, if cautiously, one just a few hours ago, General Amos Yadlin, a former military intelligence director who among other things was one of the pilots bombing the Osirak nuclear reactor in Iraq.
5) Finally, while powerful elements in Iran have certainly supported various foreign terror groups, Iran itself has not invaded a neighbor without having first been attacked since 1765. Those suggesting some Hitlerian drive to conquer neighbors by the Iranians are simply ignorant of history.