People are looking at Wiki again, probably due to popularity of blogging.  My take on Wiki is that there are some good ideas in Wiki, but there are severe inherent weaknesses that usually leads to an ever growing pile of mess.

Peter Morville wrote about Trust by Design, a key component of Wiki, but fails to mention the downsides:

• Difficulty of evolving Wiki content due to social and structural constraints
• Inconsistent quality, style, and direction

If Blog is an one-mensional animal with a single continuous stream of consciousness, Wiki is a N-dimensional animals with many segmented strands of consciousness.  While the two are related on the surface, they are two very different beasts.

UI-wise, Wiki is like a fun house for cheery gully dwarves, endless interconnected rooms with five-feet high ceiling and no housemaids.  Think neck pains and perma-mess.