Standard model partial unification scale as a guide to new physics model building

In the Standard Model, partial unification of the non-Abelian running gauge couplings is achieved at the 32 2.8 & times; 1016 GeV. Elaborating on this fact, we discuss a simple general parametrization for the new physics corrections leading to full unification at some scale MX. We show that for any new physics model such that the corrections to the non-Abelian couplings are equal (or nearly so), MX is equal (or close to) the partial unification scale & micro;SM32 ; the latter scales could be disentangled only if the corrections to the nonAbelian couplings are significantly different. We explore how the parametrization works for some relevant models with new physics below MX, as low-energy supersymmetry, split supersymmetry, etc. As for models with a desert up to MX, we explore, in particular, how the parametrization works for string-inspired corrections; we find a phenomenologically remarkable possibility for unification at about 100 TeV, suggesting a low string scale, in addition to the more conservative possibility for unification at & micro;SM models with power-law running/threshold corrections, we also outline an interesting connection with the number of fermion families propagating in the bulk.