Immersion Schools are schools where children are enrolled in a program K-6 where they learn to speak a fluent second language. This however is different than being raised in a bilingual household.
I recently talked to a friend who worked in an Immersion school. The language taught was Mandarin Chinese. The ratio wasn't necessarily limited to people of Chinese decent, but was very diverse. The second language was viewed as an academic achievement and was acquired for future goals.
I think this is a very good thing to look into. We should start children learning languages in younger years where they still have the plasticity to move farther ahead in the language. This also teaches cultural diversity and understanding. It creates an environment where children can learn about a culture different than in the one they live in.
I myself took German for 3 years but it was in a setting where i learned for an hour a day and was brief in its descriptions. It would have been much better in my opinion to learn in an environment of 2 languages.