The clash between wikis and blogging
Suppose, as Phil Hollenback does, that you blog with a simple wiki environment not by augmenting it with blog features but by outsourcing the chronological navigation to Twitter, Facebook, and the other social networking environments where many of your readers probably already are. After all of this, is there any real difference between writing a blog and writing wiki articles?
My answer is yes.
(A disclaimer: this is a philosophical digression from what I believe that Phil Hollenback is doing, which is more or less using a simple wiki as a blog datastore. I think that that's sort of a neat hack that leverages social websites in an interesting lazy way, although I think it has drawbacks for getting people to explore your blog once they've landed on it once.)
At its heart, blogging is fundamentally a mindset, an approach to writing of 'write it and move on', of putting major corrections and updates in another entry (or very prominently marked in the original entry). This is fundamentally incompatible with the wiki approach to writing, where a wiki page is a living document that may be revised continuously.
Blog entries are mostly frozen once published not because of technical requirements but by social convention. Well, 'social convention' is too mild, because in the large blogs are conversations (even if no one ever replies out loud, you are in a dialog with your readers) and it's extremely hard to have a sensible conversation if someone is constantly revising what they said.
If you present something as a blog people will react to it as a blog, including expecting these social conventions. If you then approach it as a wiki and revise things out from underneath your readers, they will get angry because your revisions destroyed their commentary (and probably made them look stupid) by removing what they were commenting on. 'Commentary' here is more than actual comments on your entry, it's also things like their own blog posts in reaction to yours.
(I have written about this before from a different perspective, here.)
This is kind of abstract, so let me make it concrete with an example; as it happens I have a good one handy. Yesterday's entry is about a quite useful way to list file locks on a Solaris fileserver, and adds some additional information to an earlier entry from 2009. This is perfectly sensible in a blog, and perfectly insane in a wiki; in a wiki, I would have a single article on 'listing file locks on Solaris' and I would have just augmented it with the new information.