As a joke someone posted a workbench 1.3 screen in one of the OS4 screenshots news items.
If I get OS4 and someone makes that skin, I'd probably use it just for comic effect :-)
That tells you something about how much I care about the look of it. I tend to agree that functionality is what I'm after. GUI effects like transparency are nice, but I'll spend most of my time browsing the web or coding. Focusing on what I'm doing rather than how I'm doing it.
I think the look of the OS will evolve as people start to develope software for it and more is known about what it can do and the direction people wish to take it in. What I've seen so far looks like an excellent starting point.