  The development of chiral perturbation theory in hyperon phenomenology has
been troubled due to power-counting subtleties and to a possible slow
convergence. Furthermore, the presence of baryon-resonances, e.g. the
lowest-lying decuplet, complicates the approach, and the inclusion of their
effects may become necessary. Recently, we have shown that a fairly good
convergence is possible using a renormalization prescription of the
loop-divergencies which recovers the power counting, is covariant and
consistent with analyticity. Moreover, we have systematically incorporated the
decuplet resonances taking care of both power-counting and $consistency$
problems. A model-independent understanding of diferent properties including
the magnetic moments of the baryon-octet, the electromagnetic structure of the
decuplet resonances and the hyperon vector coupling $f_1(0)$, has been
successfully achieved within this approach. We will briefly review these
developments and stress the important role they play for an accurate
determination of the Cabibbo-Kobayashi-Maskawa matrix element $V_{us}$ from
hyperon semileptonic decay data.
