AveDesk
AveDesk is a program that will give you the possibility to have icons on your desktop which could update themselves. Each icon of Avedesk is in fact a desklet, a little plug-in that can virtually do anything. A desklet can be just a regular shortcut, a mail checker, a calendar, a clock, etc.
It depends on the imagination of the desklets programmer. Also, the user can set a large amount of properties for each desklet: alpha level, drop shadow, grayscaling, label style, etc.