Babble.com has a great article in defense of play-based education. It chronicles the author's journey to realizing that her daughter's play-based preschool wasn't setting her back academically, and her discovery that overly-academically-focused preschool programs can actually be detrimental. Here's a snippet I especially liked:
"What used to be a time to focus on social rather than academic readiness has become yet another cog in the educational machine. Tutoring companies even offer programs for the younger set: Sylvan Learning Centers has a pre-K reading enrichment program for four-and-a-half to five-year-olds, and Kuman Math and Reading Centers have a "junior" track that accepts children as young as three.
"All this would be fine if it meant we were raising smarter, more well-adjusted children who thrive in school. But it doesn't. A wide range of research shows that kids do best — not just in kindergarten, but throughout the later grades — when they're allowed to learn in age-appropriate ways. But many parents don't understand what that means. If they don't see worksheets and flashcards, they get scared."
You can read the full article here (Babble.com).