Information gathered from http://www.kde.org/
Looks like it is not complete, if you read deeper in , you will see that allot of items we are used to are not implemented yet. but there is a nice feature,
Windows developers are able to download previews of KDE applications for their platform. The libraries are relatively stable already, although not all features of kdelibs are available on Windows yet. Some applications already run quite well on Windows, others might not.
Looks like kde4.1 is going to go a long way with the abilities aquired when most of Linux signed deals/peace treaties with Microsoft.