Before addressing the opinion side of this, and its subjectivity, I think it is important to address the avalanche of invalid generalizations and misstatements of fact I have read here.
1] We have no reason to believe she is not playing tea time or whatever, usually, like any other little girl. In fact, she probably does.
2] We have no reason to believe she is being forced to grow up any faster than any other kid based on this one activity.
3] No random guy would be arrested for having any of these images on his computer.
4] Anecdotes, as common as they are, do not support any statement that "most" twenty year olds cannot handle fame. We simply see the cases brought to us as the norm because kids adjusting normally is not a news story tabloid editors care to print.
Now, onto opinion. Yeah, the pictures strike me as a little outside my reasonable comfort zone, but I AM the product of a prudish and sexually hung up society that sees much of the human body as intrinsically sexual. I don't believe we (Americans and like-minded cultures) experience less sexual abuse, rape, or any socio-sexual dysfunction than less hung up cultures. In fact, I wouldn't be surprised to find out our approach could be statistically demonstrated as more harmful by those measures.
It's not just that we react differently to sexualization; we actually see it where others don't. I'm not saying there is nothing suggestive to see here, but I'm not sure our perception of harm is rational. As for the pedophile thing... I'm pretty sure those folks are the way they are, and a magazine spread like this isn't going to affect that in any way, shape or form. If you mean this in terms to making this particular girl a target, I suspect she has more watchful, concerned eyes on here than a lot of kids, and I'm sure that the attentions of pedophiles are drawn by what you and I would consider sexually innocuous. If a dude digs little girls, he probably digs little girl clothes. Just a hunch.