The USB 3.0 port in this case is not just a USB 3.0 port, as it's also used to connect to Sony's Power Media Dock. This in itself might not seem all that special, but the matter of fact is that the Power Media Dock connects via a super-thin optical cable using Intel's ThunderBolt interface. The issue here is that Sony has once again come up with a proprietary solution and completely disregarded the mini DisplayPort connector used by Apple and every single ThunderBolt device that will launch. Hopefully it'll be possible to use some kind of adaptor to take advantage of these devices, but it doesn't seem very likely.
The special connector for the Power Media Dock also attaches to the power connector on the notebook, but what we don't know is if the dock can draw power from the notebook. The notebook power adapter connects to the Power Media Dock and would power it and the notebook through the dock connector. Apologies for the slightly poor picture of the Power Media Dock, but there wasn't one we could get a picture of all the ports on. At the rear of the dock you'll find a D-sub, HDMI, Ethernet, USB 3.0 and USB 2.0 port. There's also a top-mounted USB 2.0 port underneath a flap. Once again, we don't really get the inclusion of the D-sub port and we'd much rather have seen a DisplayPort connector or even another HDMI port.
However, the Power Media Dock also incorporates an optical drive and Sony will offer various options, although these are market dependant, but at least in some markets there will be a DVD-RW, Blu-ray ROM or Blu-ray writer to choose from. Oh yes, there's one more thing inside the dock, an AMD Radeon HD 6650M GPU with 1GB of DDR3 memory. This is where ThunderBolt comes into its own, as it allows the signal from the GPU to be feed back to the notebook and as such you can get GPU accelerated graphics on the notebook screen. Up to an additional three screens can be connected to the notebook using the ports on the notebook itself and on the dock.