Imagine posts and comments flowing from blogs to wikis like the way streams feed into lakes.  Got the picture yet?  Now think of a blog category as a wiki page.  The picture changes so that the blog becomes a mountain and categories become the streams running down the side of the mountain in all directions toward wikis into which streams from other mountains also feed into.

The resulting picture you have in your mind is the 10,000 feet view of how I think blogs and wikis should be connected.

Update #1: Here are some decorations to complete above picture:

• rain is the news that bombard us daily
• rocks that form the mountains are our experiences
• volcanic eruptions are our rants
• flash floods are sudden spikes of activitiy
• clouds are news generators like North Korea or Saddam Hussein

Silly, but I like to garnish mental images.