Zak picked up on the discussion at Joi's, and Mark commented:
I don't agree with Kevin Marks when he says that conversation is diluted and washed away with wikis.
Signal to noise is increased after discussion over a period of time by distilling it to its main points. To get the data to the reader in the best possible way. (sometimes conversations can get heated, and often conversations are over many months.)
Wikis often act like Weblogs, example is thread mode, one post after another. But the benefit with wiki is that later some one can refractor the conversation to the important information.
He's missing my point a bit. You can do wiki-like things in blogs, and blog-like things in wikis, but you have to work at it. Blogs don't make subsequent editing easy; Wiki's don't make attribution and temporal order obvious. (Did I just refactor his comment? hmm.)
This reminds me of the cross-blog Sapir-Whorf discussion going on.
Language does not limit thought, but different languages do affect how the thoughts end up being expressed and communicated. Some things are easier to say in one language than another - English doesn't have a (formal) third person imperative, for example, which makes translating the Lords Prayer from Greek hard.
It is not inevitable that blogs become personal, wikis become consensual, and mailing lists become confrontational, but that is the tendency of each form, much as Frayn shows the tendency for formal writing to concatenate cliche in a Markovian manner.