The Universal Naked Driver is a one-install driver that works on HTC, Samsung, Asus, among a reported 250+ devices to provide ADB, Fastboot, and APX support. So if you have multiple devices you don’t have to hunt down and install multiple packages, just this one.
If you have multiple Android devices, chances are if you’ve rooted one you’ll want to root the rest. When you’re just dealing with one line like the EVO there’re no issues, but throw a Galaxy Tab or something in and you have to download another set of drivers or sometimes manufacturer bloatware.
The UND has been around for a while, but just got an update to allow for a lot more devices and some minor bugfixes.
If you’re only running one set of phones or devices and are otherwise happy, this probably isn’t a requirement for you. If you have 3 EVOs, a Nook, several Samsung and ASUS products coming in and out the door, it’s a godsend having one driver that won’t trip over the others.
The Universal Naked Driver works on 32 and 64-bit versions of Windows XP, Vista, and 7.