To Skip a Grade or Not To Skip

Marty Nemko, author of the November/December Speaking Out article, writes that high-ability students are better off skipping a grade than remaining in the same grade in which the teacher would need to offer differentiated instruction. “Grade skipping instantly gives high-potential students a much more appropriate education without imposing more work on teachers than they’re likely to do,” the article states.
Are you more likely to encourage grade skipping or differentiated/gifted instruction in your school? What do you believe are the pros and cons of grade skipping?