Here's a scary idea.. A plugin that can aggregate feeds from other
locations. Presumably there would need to be a cron job to build the wiki
periodically, and each time it's built any new items would be turned into
pages etc. There might also need to be a way to expire old items, unless
you wanted to keep them forever.

This would allow ikiwiki to work as a kind of a planet, or at least a
poor-man's news aggregator.