Over the past few months, I've been quietly reworking some parts of Mimír. One of the changes was the aggregator replacement (see the architectural overview for reference). The other part is the news bot, that consumes publish-subscribe notifications, stores items in its database and sends out messages to end users. To replace the Perl implementation of this component, a brand new one has been written in Python using the Twisted framework.
Why these replacements? First of all, there were a number of issues with the old implementations, mostly dealing with faults in interpreting incoming items. This sometimes resulted in the news page being horribly deformed. That should be fixed now. The aggregator cleans up all bad HTML and the news bot now correctly processes the incoming items without doing erroneous extra entity unescaping.
Secondly, having these new implementations makes it easier to change the format of the publish-subscribe message to conform to Atom over XMPP. Among other advantages, that would solve getting duplicates because of changing URI schemes, and allow for new features like linking to item enclosures in the Mimír messages, like sneakin suggested recently. Another feature could be a preference to only get item summaries in notifications or pure publish-subscribe notifications instead of the text messages Mimír sends now.
Another change to Mimír is the addition of an actual Mimír logo, contributed by Intosi. Thanks for that! I added the text part, but that might still change. The news paper reading guy stays for sure, though.