Jeremy Lin is the first Asian American to enter the NBA in a long time. Exactly how long, I'm not sure, since the article only says that "He became the first Asian-American player signed by the Warriors since 1947." (What about the other 29 teams?)
Incidentally, if that 1947 date is correct, then the NBA actually had an Asian player before it had a black player (1950), which is . . . strange.