With the 1.2.0 release of libwdi, which, for those who don't know, is a library aimed at making the installation of Windows USB drivers as simple and as non intrusive for end-users as possible, one of the most exciting features brought forward is WCID device driver support.
WCID, which was brought to the limelight with Windows 8, and which stands for Windows Compatible ID, is a set of additional USB Descriptors one can add to a device firmware, to make the OS automatically identify which type of driver should be used, and potentially automatically install it. In other words, what WCID does is bring the Plug-and-Play functionality that exists for HID or Mass Storage, to any USB device.
Thus, as upcoming Windows 8 comes with a WinUSB WCID driver, if you currently produce USB devices that require driver installation, you should seriously consider converting them to WCID as it'll make life a lot easier for everybody.
This is also good news for libusb-1.0 users, as libusb-1.0 relies on WinUSB for generic access on Windows, which means that you can actually produce libusb-1.0 applications for Windows 8, that do not require you or your users to take care of any driver installation. And for earlier versions of Windows, up to Windows XP SP2, libwdi and its friendly installer application Zadig can make it very easy to proceed to the one-off installation of the WinUSB (or libusb-win32 or libusbK) WCID driver, to make those platforms behave in the same way as Windows 8.