Wikis I believe are more essential because it can provide information about the world. According to a New York Times article "Wikipedia to limit changes to Articles on People " by Noam Cohen " Roughly 60 million Americans visit Wikipedia every month. It is the first reference point for many Web inquiries — not least because its pages often lead the search results on Google, Yahoo and Bing. Since Michael Jackson died on June 25, for example, the Wikipedia article about him has been viewed more than 30 million times, with 6 million of those in the first 24 hour". You can just see the significance and rapid growth of wikis.
Convergence is very important in todays networked world because it brings people together creating interaction/connection. Different forums/ social media even connects people together. Convergence I believe is the key to interaction in todays world. Blogs can be used for collaboration because like for example you have your own blog and you comment on a specific topic which will lead to people seeing your comment and adding on to that. They may agree or disagree but it will lead to collaboration one way or another. I actually can't think of a new way to use wiki because I believe that it has it all.