From the roadmap list:
"Improve transcoding tracking with database tables for registering failed transcodes, time taken per transcode, allow users to flag files as not playable or a visually broken transcodes."
This is a pretty vital thing for rolling it out to production I think; we'll need to track how things are going and be able to distinguish between "hasn't happened yet", "failed for some weird reason", and "failed horribly in the actual transcode". :)
Showing transcode status on the file page is also important so users don't feel confused by why some things don't work for a while.
Version: unspecified
Severity: normal
URL: http://www.mediawiki.org/wiki/Extension:TimedMediaHandler