When the final version is completed, it will be released. I paid only once and v3 is essentially a free upgrade for me, therefore I am not going to demand things like ETA or certain customization features just to suit myself along with the selected few.
By the amount of demands heard on the forums, Max should really start charging money in order to upgrade to v4. A lot of people seemed to have forgotten that they are getting a free upgrade to Poweramp v3. An app and it's UI, is based on the vision of a developer on how he envisions it, while taking comments into consideration. In my opinion, when an upgrade is free, it is self-entitled to demand anything. Besides, Max has given the skin makers ability to skin the app UI as their creativity allows them to be.
If one cannot live with the current UI, they can wait for a skin that suits them.