This is very well known here in the United States. A lot of people utilize this that I know of for a variety of different reasons. If you do a lot of stuff on the Web, you have most likely come across Wiki or at least heard of it. If you do any sort of collaboration on the Web, you have definitely heard of it. If you ever work in Open Content related material (my whole Web site is open content), you have definitely heard of it and probably used it once or twice. Most information searches on Yahoo or Google will turn up at least a couple of references to Wiki so it is pretty hard to miss it these days.
But it is true what the article states: many mainstream media do not really cover it in any great detail, at least that I have seen. But it is just one of those things that gets word of mouth and becomes one of those well-known things, I guess.
I have just started to explore the possibilities of Wikis for some of the information sharing that is so critical in projects.
My current focus is TikiWiki (Like Aatish said, a lot of whacky names), which has Wiki, Blog, CMS and a lots more capabilities.
And is Open Source.
Check it out: on http://tikiwiki.sourceforge.net
Wikis are great - at my last job, we used them in the entire IT department for information dissemination and pretty much anyone who wanted to post info could (and did). The danger with using wikis for that purpose (especially in a cutting edge tech shop like my last job) is there's the tendency to replace standard documentation with wiki content and for requirements and test documentation that is not always the best thing. I will say it was great for seeing how the dev team (they were an extreme programming shop) seeing their user stories and logic - it helped to take some of the "mystery" out of the apps.
We use a wiki at work also. What doesn't work well is when you use it as a repository for requirements. Our old PM used to put up anything to do with the product in a spiderweb of links that only he could understand and then take you to task for not knowing something that was up on the wiki.
Our QA team uses the wiki primarily for setup instructions for hardware and software. This has proved invaluable. It really helps that it's so easy to modify as instructions often change.