From my Bloomberg View column (read the whole thing, as they say):
Stuxnet now appears to have been a more perishable virus than previously thought. Signs are abundant that Iran is accelerating its manufacture of low-enriched uranium, the necessary precursor to highly enriched uranium. The Federation of American Scientists reported in January that "calculations using IAEA data show that the enrichment capacity at Iran's commercial-scale enrichment facility at Natanz has grown during 2010 relative to previous years. The boost in capacity is due to an apparent increase in centrifuge performance."
This latest IAEA report buttresses the federation's finding, noting that inspectors who had recently visited the Natanz facility now believe Iran is producing low-enriched uranium at a faster pace than before the centrifuges were hit by Stuxnet. Various Western intelligence agencies and independent analysts think that the Iranians already possess enough low- enriched uranium to produce two or three bombs.
Iran's nuclear energy chief and Vice President Fereidoun Abbasi was quoted Wednesday by the official Iranian IRNA news agency as saying Tehran plans to soon set up the more advanced type of centrifuges, suitable for higher-level uranium enrichment, at the Fordo site near the holy city of Qom in central Iran.