WhatsApp for Windows Phone 8 devices has received an update today to v2.11.356. The new update does not include any new features, instead it includes a fix for issue with reception of broadcast messages.
The update does not yet include the ability to send music files, but we believe this may come in a future version.
The update to the app can be found in the Windows Phone Store here.
Thanks to Prasad and Marcel for the tip.