Will we have Wikis in ten years? I don't know. Maybe something else will turn the Wiki into the Gopher of 2010.
Whatever comes along, I hope it preserves some of things that make Wikis work. Not all of these features are obvious, so I'll provide some personal background.
I use a Sharepoint* Wiki to manage all the information surrounding some new software we're developing. Not everything goes into the Wiki, but everything I work with has a Wiki pointer. It's where I go to find things.
I use the Wiki because Search Works for Wikis. It works for the same reason that full-text search works so well for email. The units of information are small (1-2 screens instead of 100 pages), titles can be descriptive, and author and date metadata are available. Wikis have the added advantage of the hyperlink enabling link weighted search results.
I can find things in the Wiki very quickly.
Whatever replaces the Wiki in the next generation of tech churn, I'm hoping it will be as Search friendly as the Wiki of 2009.
* How do I know humanity is doomed? Sharepoint 2007 is a fantastic commercial success -- and it's bloody awful. That's another story though.