I'm with 4under4. I think kids are starting too early these days. My DD is born in sept so after the early enrollment cut off. She was well and truly ready for school the year before she actually went. But in NSW they ask for BC's and I would not have lied anyway. We just did extra stuff with her while in pre school (pre prep in SA?). She was way ahead in kinder and still is in Year 2 but that has been great for her confidence levels.
I would just enrol your child the year she is meant to go and look into extension programs the school might have for her.