DesktopApplicationContext currently sets the Window icon into the host frame using java.awt.Window.setIconImage(Image). However, since Java6 there's a new method called setIconImages(List<Image> icons) to set multi-resolution icons, e.g. you can set a 16x16 icon for the window title bar, a 48x48 icon to be shown in Microsoft Windows' task switcher, or a 64x64 icon to be shown in Windows Vista/7 Aero task list. (It is up to the runtime implementation to choose an appropriate icon from the list provided by setIconImages().)
Without the possibility to set multi-resolution icons the OS scales the image either up or down to fit the current environment. This might lead to poor results.
Suggestion: add a new method setIconImages(List<Image>) method to pivot.wtk.Window and, if set, use it in DesktopApplicationContext. Or maybe add setIconPictures(List<Picture>) to get around the issue of downcasting to Picture in updateFrameTitleBar().