  In view of the extensive evidence of a tight inter-relationship between
spheroidal galaxies (and galactic bulges) and massive black holes hosted at
their centers, a consistent model must deal jointly with the evolution of the
two components. We describe one viable model, which successfully accounts for
the local luminosity function of spheroidal galaxies, their photometric and
chemical properties, deep galaxy counts in different wavebands, including those
in the (sub)-mm region which proved to be critical for current semi-analytic
models stemming from the standard hierarchical clustering picture, clustering
properties of SCUBA galaxies, of EROs, and of LBGs, as well as for the local
mass function of massive black holes and for quasar evolution. Predictions that
can be tested by surveys carried out by SIRTF are presented.
