Would Bilingual Education be a good Teaching Method for those students whose First Language is other than English?

Researchers and proponents on the matter State that Bilingual Education will help the non English speaking students to keep up with their academic subjects, like math, science, social studies, while they are learning English. The benefits of Bilingual Education will be especially seen on those students that start school in English during their Middle and High School years. Then, the transition to English only classes would be done according to their mastery in English. In this way the non English speaking students will level with the English only students. Giving them the opportunity to be able to integrate and contribute to better our society.
One of the Bilingual Education program forms that has been more successful, according to the researchers, is the one where the students are taught in the second language (English), but the students are allowed to ask questions to their teacher in their first language (bilingual teacher), who answers the questions in the second language (English).
Another advantage of the bilingual program is that the students whose first language is other than English will continue developing their language skills in their first language, these language skills would be easily transferred to their second language as they master that second language.
I would like to add that I am not stating that Bilingual Education makes it easier for students to learn English, but it will give the English learners a way to keep up with their school curriculum, and become bilingual at the same time.
It is important to state, that second language mastering is not the same as conversing in English (Basic communication Skills -BICS). What the experts mean in language mastering is that the students Cognitive Academic language proficiency (CALP) will be leveled with their age and grade level. The two are two different sets of skills.
In 2001 "No Child Left Behind" made all schools English only, leaving Bilingual Education behind.
Do you think that "No Child Left Behind" has failed the students whose first language is other than English? Behind academically, and without the opportunity to be able to pass the GHSGT, integrate to society, and fulfill their dreams.
http://www.wikipedia.org/wiki/Bilingual_education