Will not be European at all.
His name is David Blatt, and he's American. No wait, he's Israeli.
A TrueHoop reader pointed out to me that Blatt is routinely described as one or the other. It depends who you ask, and when and where you ask them. Sometimes he's even European. (He lives in Turkey, where this season he will coach Efes Pilsen, and he's the coach of the Russian national team that just won the EuroBasket tournament.)
The dichotomy is evident in a Jerusalem Post profile by Allon Sinai. In the first paragraph, Blatt's described as "the 48-year-old Israeli coach." Then several paragraphs lower there is this quote from Israel coach Tzvika Sherf (my emphasis):
"If a European coach will reach the NBA in the coming years it will be David," Sherf said. "David is very similar to Phoenix Suns coach Mike D'Antoni. They're both Americans who coached successfully in Europe for several seasons. David has the vision, ability and contacts to get to the NBA."
For the record, Blatt was born in Boston, and wikipedia describes him, accurately, it would seem, as an Israeli-American.
UPDATE: Chris Sheridan's profile of Blatt.