Plex sent over an email with the details of what they will be adding to their service:

Audio Fingerprinting plus Enhanced Music Recognition and Artist Info via Gracenote

Plex now uses Gracenote, the leader in music metadata and discovery technologies. Gracenote is the industry standard for music recognition and is supported by the largest source of metadata, featuring descriptions of more than 200 million tracks. Plex has added Gracenote's world-class matching via audio fingerprinting to ensure the accuracy of the information associated with the music in your library, such as artist, album, and genre. Regardless of the original source and associated metadata (or lack thereof), songs can be appropriately tagged. Plex now also fully supports one-click import from iTunes, so you can easily import all of your iTunes playlists, smart playlists, ratings, and more.

HD Music Videos from Vevo

Now, Plex Pass subscribers can watch their favorite music videos matched with music from their personal library. Taking advantage of Plex's rich audio and video streaming capabilities, these HD music videos can be streamed to any mobile or home device using the Plex app to create the ultimate music experience.

Mood and Genre-Driven Playlist and Listening Recommendations

Plex will now allow you to create personalized Plex Mix playlists with the click of a button based on Gracenote's descriptive information about a song such as genre, mood, and tempo. It also features a robust recommendation engine for re-discovering songs in your music library.

Best-in-Class Format and Streaming Support

Plex natively supports all major audio formats, including full support for FLAC. Plex transcodes your music files on the fly, if needed, automatically adjusting format and quality based on bandwidth to give you the best playback experience from any chosen device