Chuq's essential point is that Apple's employees do a lot to communicate and interact with the public - they just do it over traditional systems (like email lists) for the purposes of helping and solving problems. Further, 'blogging' is just one more way of communicating (albeit a new and hyped one); it isn't an end-all solution for these purposes.
While I think Chuq makes some great points about the focus of blogging and the importance of considering it as a tool for a company like Apple, I still think the company could use one, especially in light of one of its many facets as being closely involved with creative media (see: iLife, which they even brag about on TV). While blogging doesn't have to become a public focus for the company, it certainly wouldn't be difficult to fire one up, and having a blog or two for anything from pimping new products (see: the Google Blog) to offering an easily accessible forum for discussion couldn't hurt (after all, not everyone likes checking in on forums or having one more email list to organize), and they could capitalize on a popular and buzzing new medium. The blog(s) could be treated with a formal touch (like many company-focused promotional blogs) or have a more personal touch from a company-sanctioned individual, like the Scobelizer. Of course, being powered by iWeb, or having a corporate Photocast (or podcast!) couldn't hurt either.
Ultimately though, I think one of the good points Chuq makes about how well (yet quietly) Apple's employees actually are communicating is the true Achilles' heel of the idea of an Apple blog to begin with: most of the communication efforts of Apple's employees are quiet or under the radar - right where the company wants them to be. Apple, like most of its products, has a very shiny, polished exterior, which is exactly the kind that does not lend itself to opening the holes and flaws that blogging would puncture, no matter how personal or cute they may seem. One only needs to glance at the company's quiet handling of problems like battery recalls and MacBook RSS to see what I mean. Apple may be a purveyor of some of our favorite creative and communication tools, but donning a more personal side by *using* them just doesn't seem to be in the cards.