I think KDE should switch over to compiz and drop kwin. Wait, hear me out. Since compiz is very plugin based, this would allow the desktop environment to load its own plugins when the environment is started, making compiz look and act however it deems necessary. Plus, this would mean that GNOME (if they choose to switch as well) and KDE would have a common window manager to both work on and improve together. This would also mean that if I liked some effect that GNOME uses, I could use with KDE and vice-versa. Of course, this would require that compiz be able to run in an environment without AIGLX and XGL while still being usable. By using a common environment, developers can target both desktops equally well. I know I'd prefer to have this functionality.