Since Wikipedia doesn't have ads (and I'm guessing gets no real benefit from number of clicks), maybe this could be a nice way of lightening their server load and reducing some of their costs.
However it suffers the number one torrent issue: they do not tolerate change. This means that
- When an article changes, you need to generate a new torrent - When a new torrent describes the archive, it needs to be downloaded from scratch by all peers, so that the maximum number of peers are available for a newcomer.
I hope you'll understand that this is not the official way to distribute archives...