Resumen
The first ALMA antennae arrived in Chile last month. Thus, the most visible part of the observatory construction is now underway. During the next two years a dozen antennas will be commissioned and a first call for proposals will be issued. Even the early-ALMA array, having 12-24 commissioned antennas in the years 2009-2010 will offer outstanding new research opportunities. By 2012 ALMA should be in full operations, allowing studies at submillimeter wavelengths matching the optical spatial resolution and offering unequaled sensitivity both in continuum and line studies. In this talk I will focus on the ALMA observatory from the observer's point of view. In particular, I will talk about some of the key issues during the first years of ALMA operations, and conclude with the expected capabilities of the complete ALMA observatory by 2012. The first few years of operations ALMA will not have the submillimeter imaging quality and sensitivity expected from the full ALMA array; however, it will still be much more sensitive than current instruments, and it will also open new atmospheric windows. I will draw on examples from the main ALMA science drivers, including the study of the ISM, disks, and galaxies. The next three years will be essential to ready the community for ALMA use and the first results will likely be reported in the next Regional Meeting.
