We often skip students in early primary grades (K-2nd) at my school - beyond third grade, it becomes a bit of a guessing game as to how a student will/can do. When you're in middle school, and have missed a particular topic/subject due to being skipped, it can be more of a hindrance to realize what was missed due to a grade skipped than a blessing. Primary elementary school grades are an awesome time to explore the option, though. Make sure the school's TD/Gifted teacher is involved in the process and helping classroom teacher(s) differentiate for your child, and meet their needs. Just because you have skipped a student, it doesn't mean their needs will simply be met with a challenge.
On a side note, for those that mentioned either they skipped a grade or had kids that were...what's the benefit of skipping a grade besides being "challenged?" I have a coworker that is strongly against it, saying no one "wants to rush to more homework, paying bills, etc." Then again, I just think she's lazy, so lol...