  State-of-the-art predictions for the Higgs-boson production cross section via
gluon fusion and for all relevant Higgs-boson decay channels are presented in
the presence of a fourth Standard-Model-like fermion generation. The
qualitative features of the most important differences to the genuine Standard
Model are pointed out, and the use of the available tools for the predictions
is described. For a generic mass scale of 400-600 GeV in the fourth generation
explicit numerical results for the cross section and decay widths are
presented, revealing extremely large electroweak radiative corrections, e.g.,
to the cross section and the Higgs decay into WW or ZZ pairs, where they amount
to about -50% or more. This signals the onset of a non-perturbative regime due
to the large Yukawa couplings in the fourth generation. An estimate of the
respective large theoretical uncertainties is presented as well.
