When I was growing up in Canada, I was in a French immersion program and I was rarely bored. Our immersion program was 100% French until grade 6, 50% French for grades 7 & 8 and then 25% through high school. I now live in the US and am considering immersion programs for my son. However, my concern with the immersion programs that I've encountered here is that they're only full immersion for a few years. For instance, one school is only full immersion up to 2nd grade, largely due to the testing required for No Child Left Behind (I'm told it used to go up to 4th grade). So, I imagine it would only be challenging for a few years. Perhaps others can provide some insight on this?