I use Winamp. I use versions 2.81, 2.91, 3, and 5.05.
The things that first attracted me to Winamp were:
It loaded quick and used a small amount of memory resources.
I like 5.05 because of the cool skins people made for it.
I always used 2.91 the most and continue to, that version was the best for my needs.
I think they should continue to develop Winamp.
My advice would be to go with low memory usage, and make it easier to make skins for Winamp, I think this could bring new beginners into skinning.
Winamp was the first app I learned to skin, Winamp is responsible for introducing me to the world of skinning.
I would be sad to see Winamp no-longer developed.