Actually I have begun some work on this.
Users of our wiki have always complained about site slowness and recently I have tried to speed things up as much as possible. But the conclusion I have reached is no matter how many accelerators or caches are added to the server, Mediawiki is just slow. phpBB3 pages are loading 5-10x faster on my web host. Mediawiki shows no signs of trying to revamp their software to make things faster.
I had an idea for a new system to make page loading go really fast. Wiki articles are mostly static. Why bother storing them in the database and parsing them every single time someone loads a page? I think every wiki article could be saved as a HTML page and simply included when building the article. This could also be accomplished with templates, rather than having to have a job queue to rework every page when a template changes. If you have HTML caching enabled then it would be the absolute fastest way to display content, requiring next to no overhead for an unregistered person to view your wiki.
I hope to have something for people to try out in the near future.