There have been several other attempts in to setup similar wikis. For example, Scholarpedia is exactly this model of a peer-reviewed topical encyclopaedia, but for mathematical sciences. There were two comments from other Slashdotters, complaining that a group of academics, or any group of people will often struggle to reach consensus. But I think that there are qualitatively different types of disagreements. Some are about writing or presentation style ("where the place the word 'the'"). But, some are more substantive, especially in topics that are not entirely resolved. For example, there is little disagreement that Newton's laws are wrong, but nearly exact for certain spatial and time scales. But, if you were to write an article on information coding in neurons, there are probably as many opinions as there are labs working in that area!
If only Wikipedia became more widely used than it is presently, especially in academic circles, then more groups will be interested in having articles reflect debates. To reflect different opinions is particularly important in fields involving subjectivity (pretty much every thing other than Mathematics). If there is enough interest among academics in Wikipedia, then the current state of debates on various topics is bound to be reflected in the articles.
Given that Stanford's plato website is simply a fledgling effort, I do not see why it is newsworthy. If for example, someone cited an article from the plato website in a peer-reviewed journal article (and reviewers accepted it), that would be newsworthy. Short of that, it is simply yet another effort at collaborative information sharing. It cannot be newsworthy simply because it is from a well known university.