I agree with the points made about children who can read words, but have very little reading comprehension. To me, what's the point if you can read all these words and not understand what the heck you're reading. My son is very smart, but I try not to keep pushing him to the next book because I want him to enjoy being a child just as much as advancing in his academics. A friend of ours would brag about how her preschool son could read at a third grade reading level, but when he got into kindergarten, the teacher held him back because his reading comprehension was really poor. So it's not always just being able to "read" that's important, but getting the bigger picture of what and why they're learning what they're learning, if that makes any sense. If your child is 3, I don't think it would hurt him to learn his phonics, but maybe focus on things that interest a 3 year old that is a learning process. Like for example, grow a plant with him and show him how you first plant a seed, water it, give it sun, etc... It's fun for a 3 year old and they're learning at the same time about order, science, etc...
Lisa