  The past decade has seen a large progress in the X-ray investigation of
early-type galaxies of the local universe, and first attempts have been made to
reach redshifts z>0 for these objects, thanks to the high angular resolution
and sensitivity of the satellites Chandra and XMM-Newton. Major advances have
been obtained in our knowledge of the three separate contributors to the X-ray
emission, that are the stellar sources, the hot gas and the galactic nucleus.
Here a brief outline of the main results is presented, pointing out the
questions that remain open, and finally discussing the prospects to solve them
with a wide area X-ray survey mission such as WFXT.
