Winamp 3 is harder to skin, i.e. you actually have to work at it, but it is actually easier to make a *nice* skin. The problem with Winamp 2.x was that it was hard to skin it *well*, but it was easy to skin, especially with skin generators. What you ended up with was a ton of half-ass skins that were cranked out in ten seconds, burying the small minority of good work. Winamp 2 was very confiing and difficult to make anything very 'new', due to its static components.
Now with Winamp 3, you have freeform skinning, potent scripting, and even the Wasabi SDK to mess with. So while you will actually have to work to skin it (which will be new to 90% of Winamp skinners), you will have a much easier time making spectacular looking skins.