It’s requires a pretty unique situation to need a USB device over Ethernet but it certainly can come up. I stumbled across the AnywhereUSB device. They could come in handy for enable USB use from VM servers or reducing the clutter of client footprints. There are several different models available that allow 2-14 USB device connections and some models that allow serial devices as well.
All of the models support Windows XP – Windows 8 and Server 2003-Server 2012. The software and firmware is upgradable and a remote configuration utility is provided. The front of the devices include LEDs to indicate the port status. The connections are over 10/100 switched Ethernet. The 14 USB device model, Anywhere USB /14, is rack mountable and allows two Ethernet connections.