I'm not sure if I've ever seen an article on the downsides to homeschooling - there are just too many advantages!
A study was completed last year which you may be interested in reading:
Perhaps a downside could be burnout by parents, partcularly if they've been homeschooling several children for several years. Good luck!
Since you asked, NBC did a "Law and Order - Special Victims Unit" on homeschooling being a cover for child abuse. (Go to nbc.com and search for articles on homeschooling.) However, I think that is a grossly inaccurate portrayal of most homeschooling families. Like the last person said, there are only too many advantages to homeschooling that outweigh any "dangers or disadvantages."