Recently I read Doc Searls' The Chronological Web, where he argues (as the CentreSource blog entry that led me to his entry puts it) that most organizations need a blog. But what really made me sit up was this bit towards the end:

This helps, for example, when we talk to civilians who are new to the Web and want to "put up a website". Very often what they really need is a blog. [...] Updating a "site" is a chore. [...] Blogs are written, not constructed. Updating them can be as easy as writing an email. Yet there's nothing about a blog that excludes static pages.

This is about as concise a summary of the appeal of what I call wikiblogs as I could ask for. You get a blog, you get easily made static pages, and you hopefully get a decent management and authoring environment for it all. (You usually also get a very clear separation between content and visual design, often with your choice of skins.)

The other thing you get with a wikiblog is a blurring of the distinction between blog entries and 'static' pages (which may not be all that static). This is good for both sides, as each have things the other side can profitably steal. (The blog side may feel it has little to take from boring static pages, to which I have a simple reply: non-crappy navigation.)

(Another possible effect of blurring the distinction is to make people think of all of their site as more a publishing environment, a part of the 'Live Web' in Doc Searls terms, than a part of the heavyweight 'Static Web'.)

if you want examples of wikiblogs in action, see Ian Bicking or Martin Fowler (or look for people using packages like Blosxom and PyBlosxom). (Disclaimer: selections not comprehensive.)

Also see the WikiPedia page on bliki, which has more additional links than I can shake a stick at.