Status of ATLAS and preparation for the Pb-Pb run: (Plenary talk at Quark Matter 2009, Knoxville, USA, March 30th - April 4, 2009))

The ATLAS experiment took its first beam data in September 2008 and is actively preparing for the planned start of LHC collision data-taking in September 2009. This preparation includes hardware and software commissioning, as well as calibration and cosmic data analysis. The status and performance of the ATLAS detector will be discussed, with a view towards the Pb+Pb run expected in 2010.