[jbmorgado]

Not really, not in English and not in Spanish or Portuguese.

"Next Wednesday" means "Next week's Wednesday" in all cases. It's not ambiguous.

[StavrosK]

Huh, interesting. In Greek, we say "(this) Wednesday" (whichever one comes next), and "next Wednesday" (the one that comes after the next one). Weeks don't factor into it at all.