I love Wikipedia - it is my go-to reference source on the internet for most questions, especially real-life things. I love the way you can meander for hours at a time, following one link to another, going through hundreds of articles until you realise it's past midnight and you've got work tomorrow.
Can you do the same with campaign settings? Hell yes!
Some of my favourite wikis for campaign settings (not all of them D&D) include:
Greyhawk Wiki (part of the great Canonfire website)
Forgotten Realms Wiki
Obsidian Portal (where DMs can create wikis for their own campaigns)
Fighting Fantasy Titannica (ok, not D&D, but I still like the books)
These group wikis are potentially huge - Star Wars Wookiepedia (love the name!) has 85,000+ pages. Wowpedia (for World of Warcraft) has 93,000+ pages (although a lot of that is gameplay info).
Another part of my inspiration has been fantasy worlds created before the rise of the Internet - in a Dragon magazine interview with Ed Greenwood (the original creator of the Forgotten Realms) he said he had 80 boxes of notes of Realms lore at his home, while the depth of history and culture for settings like Tolkein's Middle Earth and R.E. Howard's Hyborean Age (both before the rise of D&D and other RPGs) or M.A.R Barker's Tekumel and David Hargrave's Arduin (at the dawn of RPGs) is astounding, with the internet allowing these to be increased exponentially by fan contributions (of variable quality but unquestionable enthusiasm).
Have I done the same with Kaelaross? Not exactly. The amount of effort required for a proper wiki of Kaelaross would be overwhelming. I would look at the range of subjects to be done and I would bottle out and end up playing computer games instead. Loss of confidence is a major part of my quitting projects.
This is why I have decided to do a blog instead of a wiki - regular additions to the blog about three times a week is manageable - that does not worry or overwhelm me. I just add a page every two or three days.
Nonetheless, I have tried to link pages together in a similar way to a wiki. Blogger might have its problems, but at the moment it is relatively simple to link one page of my blog to another page if folks want to find out more about a name or a subject. One thing that this does require is going back through previous posts and creating links to newer pages. This is a bit of a bore, but it can be done.