  First, we briefly review the conditions under which the entropy $S_q$ can be
extensive (Tsallis, Gell-Mann and Sato, Proc. Natl. Acad. Sc. USA (2005), in
press; cond-mat/0502274), as well as the possible $q$-generalization of the
central limit theorem (Moyano, Tsallis and Gell-Mann, cond-mat/0509229). Then,
we address the $q$-triplet recently determined in the solar wind (Burlaga and
Vinas, Physica A {\bf 356}, 375 (2005)) and its possible relation with the
space-dimension $d$ and with the range of the interactions (characterized by
$\alpha$, the attractive potential energy being assumed to decay as
$r^{-\alpha}$ at long distances $r$).
