How do I talk to my child?

With my eight-month old son growing up so fast, I've been thinking a lot about a topic that intrigues all bilingual parents - in which language do I speak to him?
I'm most comfortable in English (and later on, he'd be too). But I also want him to speak Korean. And, to be honest, speaking Korean to my son - because it's what I grew up with - just feels more intimate and heartfelt to me. At the same time, I plan on reading to him nightly and instill in him the joy of reading and love for the English language. For that, I'd need to speak English at home primarily.
This is made more complicated by my wife's intention of speaking to him in Mandarin Chinese when they're alone. I fully support this, though they'll have their own secret code. It's a small price to pay for him to learn one of the most important languages in the world.
Other parents who've gone through a similar conundrum tell me to let it be - to talk to him in the most natural way. Others say I should be disciplined and stick to one. I'm still not sure how I'll respond.
- Roger in DC