For the past few years, it's become quite popular to "red-shirt" kindergartners, especially boys. The idea is that if kids start school a little later, they'll be academically more advanced and do better (and kids who are bigger and more coordinated will do better athletically). In some cases, this may be true. School districts have been quite open to following parental directive on this front.
They have been less open, however, to going the other way, and letting a child start kindergarten early. I'm not quite sure why, but even children who just miss the fall cut-off and can demonstrate, say, an ability to read at a much higher grade level, encounter an uphill battle getting an exception.
So I'm glad to see that Colorado is at least creating a pathway for parents to request an early acceleration. According to this article in the Canon City Daily Record, parents can request testing, get a recommendation from a preschool teacher and make their case. The school district is quick to point out that only children scoring in the 98th percentile or higher should do this, but at least they are acknowledging that in some cases it's a good idea!
Obviously, in some cases it isn't too. Many gifted children rather enjoy preschool because it tends to be more flexible, and less about everyone in the class doing the same thing at the same time. But starting kindergarten early is one of the best ways to do acceleration, because it gets it out of the way early, and then (barring the need for more acceleration... which, of course, can happens with PG kids!) children can keep going along with the same cohort.