im a first generation american, my parents came here from the dominican republic when they were in their teens...
i grow up speaking both languages, and from kindergarden through the first grade i was in bilingual classes (not ESL) and it worked well because it intergrated both languages. sadly enough i've noticed that the educational system is cutting down on this program (at least in the city that i grew up in--my mom still teaches there), and i dont understand why. it works pretty well, you keep the language you were raised speaking, but you learn english as well. in two years i was perfectly bilingual.
*shrug*
not that this post had much to say really. just things that popped in my head as i read.