  Despite the lack of evidence of new physics at colliders, neutrino masses,
dark matter and matter-antimatter asymmetry of the universe require an
extension of the Standard Model. After discussing some new concepts and tools
in the description of seesaw neutrino models, such as motion in flavour lepton
space and the introduction of the bridging matrix that nicely complements the
orthogonal matrix, I discuss recent developments in the connections between
neutrino data and scenarios of leptogenesis within some well motivated
extensions of the Standard Model. Finally, I briefly review a simple unified
picture of neutrino masses, leptogenesis and dark matter based on an extension
of the seesaw Lagrangian where a non-renormalizable effective operator coupling
right-handed neutrinos to the Higgs is introduced. This operator enhances the
right-handed neutrino mixing between a coupled heavy right-handed neutrino and
a decoupled one playing the role of dark matter. Interference between the two
coupled RH neutrinos generate usual $C\!P$ violation so that one can also
achieve successful leptogenesis. Although the dark matter right-handed neutrino
escapes direct and collider searches, its decays produce a detectable
contribution to the very high energy neutrino flux now discovered by IceCube,
so that the model is predictive and can be tested at neutrino telescopes.
