First and foremost, the most welcome features is the addition of support for MTP Players and iPods. Clementine can now copy songs, remove songs etc. from these devices. If a particular device does not support the file type being sent to it, Clementine will transcode it first. Unfortunately, though, I could not get this working with my Android phone.
Another welcome addition is the queue manager. This was something that I sorely missed in the earlier versions of Clementine.
The playlist has also received a lot of attention and it now expands when the window is stretched. Not a feature, but an annoying quirk has been fixed. Another improvement in the playlist is the support of drag-and-drop.
And, not to forget, Clementine 0.5 RC 1 comes with Hypnotoad.
You can check get a more complete listing of the changes here.
Clementine 0.5 RC 1 is available for Linux, Mac and Windows. Download links below: