Thanks, everyone. I think developing the work ethic and finding the point of optimal learning are really the two issues I'm struggling with the most right now. So far, the language immersion program is great, but even my son recognizes that he's not learning much else. His school is 80/20 language immersion in kindergarten and then goes to 50/50 through fifth grade.
Honestly, I wish that school were just shorter overall. Kindergarten is 6.5 hours a day, which I think is nuts, especially considering how little he is really learning. He is involved in a couple of extracurricular activities (running club, chess, and kung fu last semester, but we will be dropping kung fu once Little League season starts), but he doesn't have the energy for anything more because his school days are so long. He had been taking piano lessons, but it was getting to be too much with everything else. School sometimes feels like time wasted when he could be doing something else he'd find more fulfilling.
Otherwise, though, he's a generally happy child. He is well-liked by both teachers and classmates, and he has a ton of same age friends outside of school. Boredom isn't yet that big a problem; lack of work ethic - not just in academics - is only just starting to be. I'm just trying to stay ahead of everything, because I don't want to look back and think, "If only I had done [whatever] when he was a little. What a difference it would have made."