(although Israel have thus far been successful in stopping Russia sell Iran the S-300 anti-air system, the most advanced one around),
Nah. It was an epic fail. They've got those now. .
Not definite. Although Russia signed a contract to deliver them, I don't believe they actually have yet. Israel has been conducting high level negotiations with Russia to prevent the sale, so there must still be something in it.
This is what wikipedia has to say:
Iran 's status regarding the S-300 system remains controversial. They are alleged to have acquired an unknown number of S-300PMU-1 missiles in 1993, potentially 300 recently from Belarus.[15] Iran claimed to have signed a contract with Russia on 25 December 2007 on the sales of the S-300PMU-2 missile system.[21] Russian officials have denied this.[22] According to senior Israeli defence sources Iran is to receive S-300s by 2009, deliveries will take place from September until begin 2009.[23][24][25] It has also been claimed that Croatia sold their S-300s to Iran.[26] Later, another claim was made saying Libya transferred S-300s to Iran.[27]. On December 21, according to a senior Iranian lawmaker, Russia has started the supply of components for S-300 air defense systems to Iran. Esmaeil Kosari, deputy chairman of the parliamentary commission on national security and foreign policy, told the Iranian news agency IRNA that Iran and Russia had held negotiations for several years on the purchase of S-300 air defense systems and had finalized a deal. Kosari said the Islamic Republic would deploy S-300 surface-to-air missile systems to strengthen national defense on border areas.[28] On 28 October 2009, if asked when Russia would deliver the systems to Iran, Ivanov said: "There have been no such deliveries to date."[29] Yet on 23 December 2009, Russian Deputy Foreign Minister Alexei Borodavkin said Russia sees no reason to cancel a deal to provide S-300s to Iran. He said ""Exports of such weapons is subject to no UN treaty or other bilateral agreements, This is why we see no essential reason to make any change in the deal," indicating that there is a deal.[30] On 8 February 2010, Iran announced that it had a "domestically-made" system with the same capabilities as the S-300.[31] Alexander Fumin has said that the delay in the delivery is due to a technical problem with the radiowave system.[32]. In 19 April 2010, Asr Iran (Iran's Era) website said that Iran could develop a similar air missiles system[33] On 11 June 2010 Russia has stopped sale of the S-300 air defense system to Iran in lieu of U.N. sanctions against Iran stating that the "S-300s fall under these sanctions".[34]. On 4 August 2010 Iran claimed it has obtained two S-300PT (SA-10) from Belarus and two others from another unspecified source despite Russian refusal to deliver them.[35] The Belarusian government has denied rumors that Minsk had allegedly sold S-300 air defense systems to Iran. "The State Military-Industrial Committee can officially state that Belarus has never held talks with Iran on the deliveries of the S-300 air defense systems", said committee's spokesman Vladimir Lavrenyuk. "Belarus has never supplied S-300 systems or their components to Iran," he said, adding that Minsk strictly complied with international arms control regulations.[36] On 22 September 2010 Russian President Dmitry Medvedev signed a decree banning the sale of the S-300 and other military equipment to Iran.[37] The sale was canceled because of United Nations Security Council Resolution 1929 sanctions on Iran. On 10 November 2010 Iran announced that it had developed a version of the S-300 missile.[38] However Pieter Wezeman of the Stockholm International Peace Research Institute has questioned Iran's ability to duplicate the Russian missile system.[39]
Essentially, nothing conclusive, just rumors.