Hi,
The default skin have been updated recently, it's now much cleaner and pleasant.
There is still some points which make the UI look a little bit old fashioned, so here they are. You could say that my eyes are too sensitive, and i won't deny : )
1 : this close button attached to this tracklist stand out too much in my opinion. It's not an important UI element because you don't need to close this tracklist, you open a new one, or you scroll below, but who is gonna close it ? I think it would be more logical to put just a cross without any background, using the color of the tracks titles.
2 : The play button there is a little bit too big too. It's taller than the album name
3 : it would look better imho if the selected item background was full with, going under the scrollbar. The scrollbar would then just overlap the content, like most apps nowadays. On most skins, the scrollbar zone have the same background color than the whole column, so it would work and it would look more clean. The tracklist which extend below each albums cover could be full with also, it would look better. (But then there is more work to do in order to see the scrollbar even above a dark tracklist, so it's probably trickier to do)
4 : There is a little vertical gap between the top of each tab and the bottom of the caption bar. I think this gap is useless visually, it would be cleaner without it.
5 : there is too much horizontal space around those 4 buttons on the right. Generally on the whole control bar, the horizontal gaps between elements aren't distributed harmoniously/regularly.
6 : the selected item background isn't vertically aligned with the text inside
7 : The search bar looks old fashioned, with this very dark border
Apart from those point, the UI since this 3.3 update look a little bit more like a modern app, which is great.