The first pre-release of AwesomeMediaLibraryManager.

Highlights of this pre-release:

Main claim to fame: Supports FLAC files with embedded cue sheets. Also supports MP3, Ogg Vorbis, even good ol' WAVs. Other formats on the way.
Player controls work.
"Filter pattern" box works. Clink on the binoculars to choose case sensitivity and whether you want to filter by fixed string, wildcard, or regular expression.
Style and Icon drop-downs in the toolbar work. Select "Windows" for that classic Win95 look!
Metadata sidebar works, displays all detected metadata and any embedded cover art.
Library caching functional, in that the next time you start the app it will remember the songs you imported last time. Only basic metadata is cached however; use "Tools->Rescan Library" to reread all the metadata.
"File->Save playlist as..." somewhat works, as long as you select XSPF format. Loading the playlist back however does not work, so.....
Drag-and-Drop mostly works. You can drag songs from the Library window to the "Now Playing" window, even multi-selections. You can also drag a song into an open web browser - even a subtrack out a FLAC+cue sheet file - and the browser will play it (at least this works on Firefox), which is pretty cool.
Much other stuff is in various states of pre-release and marginally works or is just stubbed in.

"File->Import Library...", select the root directory of your music library. File scanning will start, then metadata will be read.
Double-click on the songs that show up to send them to the "Now Playing" playlist and start them playing.