Wikipedia is Web 2.0. User generated content online, crowd sourced, the whole lot. However for sources, they only look at early 20th centuary tech, like newspapers or books. They don't value internet sources nearly as much.
That's because however much people would like it to be otherwise, "I wrote it up on my blog" is really not the same as "I had a book published by Cambridge University Press".
I think it's very reasonable not to value internet sources as much. With print sources usually you have at least an editor and at best some kind of peer review that strongly increases credibility. Citing blogs just doesn't cut it. With web sources you also have the problem of bit rot and broken links, print media can usually be obtained in any decent library for way longer than websites typically survive.
Not as much as you might think. After the Daily Mail (think Britain's answer to Fox News but with the additional benefit that you can use it to wipe yourself if you are out of toilet roll) published a story saying that Amanda Knox's appeal had been rejected, we had an enormous discussion on the Reliable Sources Noticeboard about whether to ban the Daily Mail as a source.
We didn't reach consensus on whether to do so, but you can bet that the next time they do something equally stupid, said thread will come up in discussion. A few more major blunders and they will quite probably stop being considered a reliable source on WP.
