It's not a feature that's been talked about much, but it offers multiple benefits. First, speed of file transfers with a USB 3.0-enabled PC will be faster, a welcome change from the slow speeds we're used to on smartphones right now. The other benefit will be when charging – USB 3.0 provides up to 900mA output current, higher than the 500mA of USB 2.0, so you won't have to worry about extremely slow charging when charging from your PC. In fact, there's also a 1.5mA mode on USB 3.0, though that makes concurrent file transfers impossible, so it remains to be seen if there's an option for both on the device or whether the 900mA mode is permanent.
Oh, and if you're worried about losing that micro B USB 3.0 cable and having no way to charge or manage files on your device, don't be. Similar to those backward-compatible USB 3.0 flash drives, the Note 3 will allow you to connect a standard microUSB cable as well, so Samsung has every base covered.
