  The unprecedented centre-of-mass energy available at the LHC offers unique
opportunities for studying the properties of the strongly-interacting QCD
matter created in PbPb collisions at extreme temperatures and very low parton
momentum fractions. With its high precision, large acceptance for tracking and
calorimetry, and a trigger scheme that allows analysis of each minimum bias
PbPb event, CMS is fully equipped to measure dimuons in the high multiplicity
environment of nucleus-nucleus collisions. Such probes are especially relevant
for these studies since they are produced at early times and propagate through
the medium, mapping its evolution. Inclusive and differential measurements of
the Z boson yield will be shown, establishing that no modification is observed
with respect to theoretical next-to-leading order pQCD calculations. The
validity of the Glauber scaling for perturbative cross sections in
nucleus-nucleus collisions at the LHC is confirmed. In addition, the status of
the quarkonia measurements (primary and secondary J/\psi, and the 3 Upsilon
states) will be reviewed, both in pp and in PbPb collisions.
