To believe the “how will they socialize” question is ludicrous:
Basically, according to this article, your children need to take regular “showers” in adult conversation. Not just question and answer sessions at the dinner table or in the minivan on the way home from soccer practice. They need real dialogue, and real exposure to real adult conversation. How can they do this when they are sitting in a classroom all day with 20 same-age children and one adult who has been tasked with cramming information into their brains?
Be sure to read the comments at the bottom of the article too–they raise some interesting thoughts about conversation and homeschool, and how even those who have their kids at home all day don’t necessarily take advantage of all the “shower” opportunities they could. (Like the times the mom is typing away at her blog and looking longingly at her not-yet-made bed and considering a nap rather than spending time with her kids… like… now, for instance…)