I agree with aeh. Your kid can be quite gifted and not be an early reader. This is certainly true of my DD-almost-7. Everyone notices how insanely smart she is (including, perhaps especially, verbally), but she is still following a dead-normal trajectory for learning to read.
This particular type of asynchrony creates its own type of problem in the early years of schooling. Grade level (if acceleration is allowed at all) is gated by ability to read. That restricts a gifted kid's access to actual content areas, such as science and history and literature.
I wouldn't pathologize a 5-yr-old who isn't reading yet, but it might nevertheless be worth it to try hot-housing the reading, to keep your kid at a more appropriate grade level overall. (Although, in my case, the hot-housing didn't work. She is learning to read on her own time-table.)
