I've got a media library consisting of a set of roughly 8000 MP3 (purchased from Amazon MP3), AAC (purchased from the iTunes Music Store - Unencrypted), and FLAC (ripped from my own physical disks) files. Tags are broken on a large number of these; particularly where album art is concerned. My previous standby for dealing with such matters, Tag&Rename, seems to have been abandoned by it's developer, Softpointer. Moreover, it has some pretty serious bugs that have destroyed tags on these files on multiple occasions in certain circumstances.
I'm looking for a tool that can do something similar. Most of the "Built-In-Media-Player-Tagger" tools don't know how to deal with album art correctly (e.g. both Winamp and iTunes don't update album art in the media files; they merely place the album art in their own databases), or (sadly) cannot deal with FLAC files.