My super-slim ultrabook has one USB 2.0, one USB 3.0 port, and zero ethernet ports. It came with a USB 2.0-to-ethernet adapter and it works just fine in either port. I have noticed that USB 3.0 ethernet adapters are available.
Will upgrading to a USB 3.0 adapter possibly offer a faster connection? Are ethernet connections over a certain speed being bottle necked by the limitations of the USB 2.0 connection?