How to change the printer icon displayed in the Control Panel

In Windows Explorer, go to:

%LOCALAPPDATA%\Microsoft\Device Metadata\dmrccache

And open the appropriate language-specific folder (e.g. for US it is en-us). There you will see subfolders corresponding to your installed devices. In each subfolder you'll see a folder named DeviceInformation. In that folder is the icon for your device.

You can either replace the icon itself, or you can edit the DeviceInfo.xml file and specify a different icon to use.

The location has changed for Windows 8.1. It's now:

C:\ProgramData\Microsoft\Windows\DeviceMetadataCache\dmrccache\en-US

Further, you can change the icon(s) to whatever you want using this Microsoft tool. This article describes how to use the tool.