Hi!
I'm not sure how realistic this is given the completion of the Reconquista in 1492, but...how would European life (and perhaps even the early Western Hemisphere) life have changed had Ferdinand and Isabella not expelled the Jews in 1492? Conceivably, Their Majesties could issue a proclamation guaranteeing the Jews' safety provided that they pay a special tax or something like that (unless they convert, in which case they don't have to pay). This would probably be welcome news for the Jews: after all, with the Muslims gone and Spanish nationalism all revved up, they could be next and a tax would be better than expulsion, execution, or (in some cases) conversion.
I can imagine Jewish settlers in the Spanish New World once it opens up (especially if they are subject to anti-Semitism in Spain proper -- think of the Puritans and Massachusetts). Curacao and the Dutch Antilles would probably get fewer Jews.
Anything else?
ACG