No, I have not seen it in action, I am merely going by the descriptions provided. I do not see this as providing anything additionally useful to the Windows UI, just more clutter and distraction. How is a word document icon as it exists confusing? Why do they need to "improve" it by placing a preview of the document on that small white backdrop? It's all well and good to add extra flash and dazzle to an interface, but you reach a point where it is just too much and adds confusion where there was none before.
In case you hadn't guessed, I'm a big fan of clean, effecient, non-clutters GUIs. I don't want my interface to get in the way of what I'm trying to do.
EDIT: After going through the WinSuperSite features, I stand corrected to an extent. The preview icons only apply when you're viewing in Tile mode, not list/tree view, which is how I manage my system. I still think it's needless fluff, but I step back from my "Worst. UI. Ever." comment.
