Mp3tag is a powerful and yet easy-to-use tool to edit metadata of common audio formats where it supports ID3v1, ID3v2.3, ID3v2.4, iTunes MP4, WMA, Vorbis Comments and APE Tags. It can rename files based on the tag information, replace characters or words in tags and filenames, import/export tag information, create playlists and much more. Mp3tag supports online database lookups from, e.g., Amazon, discogs, or freedb, allowing you to automatically gather proper tags and cover art for your music library.
Detailed description »

Changes in the last version:
Support for cover art for Ogg Vorbis, support for Musepack SV8, new and updated web sources (discogs, Amazon Cover, MusicBrainz), support for Windows 7, improved support for fields with multiple values, Amazon API Signing, and many other new features, changes and bugfixes.