Oh, can I play too?
With fvwm you can more or less configure every border style you want. Have you tried the themes package? Theming could be better integrated into the distribution, though.
It would be really good to have variable width titlebar buttons, rounded window borders, *box-like handles and different width of different window borders, e.g. set side borders to 1 pixel and bottom border to 5 pixels. Would make porting themes from Openbox or Fluxbox possible. I've even seen and used patches for these. Another nice thing would be an arbitrary pixmap for triangles in menu.
