Events System #1
Description
Plugin writers should be able to trigger commands based on backend events (users joining, messages in channels, pushing to github, RSS feed updates, etc...).
To make this work a publish/subscribe style system would probably be a good idea. Ie, plugins can register for interesting events which they will then be informed about.
This could be quite course (when event x occurs, fire hook) or more granular (when user x causes event y in channel z) depending on how its implemented. The course approach is the easier and simpler to write but will probably require handlers to do their own filtering.