There's really no such thing as perfect information. Gold star reviews and super credentials aren't a guarantee of good information, and so no matter what source we use for information, a critical element of that process is how we go about establishing the veracity of the content.
So, just telling kids to go to any source, whether it is scholarly journals or Wikipedia, is always inadequate if they aren't also taught how to determine the credibility of the source and identify things such as bias (which is always present).
Wikipedia actually now has a number of ways of establishing the credibility of content. They have detailed talk pages; fairly extensive guidelines; they are grouped, linked, and graded within larger project categories; they can be locked; they can be recommended for good article status; and they can be flagged for deficient characteristics (and there's probably others).
This doesn't always work. I read a Wikipedia article on adolescent sexuality the other day that seemed like it was written by a nun with a giant ruler. It was embarrassingly awful. But ANY information can be awful. I tend to think we'd be better off worrying less about what sources kids use and more about teaching them skills for assessing information in general (which seems sorely lacking these days).
The other point which could be made is that it is inevitable. Crowd sourced content such as Wikipedia isn't going to go away, while book bound encyclopedias are pretty much extinct. It makes sense to be proactive about using it as a resource. There is a lot of good content on Wikipedia and it is all linked and interactive. That makes for a tremendously valuable resource if used correctly.
I think if I were a teacher I'd have a project where my kids created and edited a Wikipedia page. It could be for their own school, for instance. That would teach them how Wikipedia works, help them understand what goes into that kind of content, and, importantly, help them understand things to look out for in terms of credibility.