USB 3.0 or SuperSpeed as the standards group calls it was a huge improvement over the past USB 2.0 standards. This was particular true for two aspects of the interface. First it was much faster than the previous USB 2.0. The move from 480Mbps to 4.8 Gbps was a ten fold improvement in the data rate and was particularly welcome for improved transfer rates with external storage devices. In addition to higher speeds, the USB 3.0 interface also improved the power capabilities. Previous ports were restricted to just 500mAh while the new standard went up to 900mAh. This greatly help on those devices that used the USB ports for power. Even with these improvements, the standards group is getting set to introduce USB 3.1 next year.
Rather than a major version jump, the SuperSpeed+ as they are referring to it is a minor revision, hence the 3.1 version number. Once again, speed and power are the two major goals in the new version. Instead of a ten fold increase in speeds, the new standard will essentially double the speed to 10Gbps. This is going to be most beneficial for those peripherals with extremely high data rates such as high speed storage such as solid state drives or even for video signals. The power should also increase slightly over the existing 900mAh which will greatly help reduce charging time with the larger number of devices (primarily tablets and smartphones) that rely on USB connectors for charging.
Of course the biggest change with the upcoming USB 3.1 standard was only just . A new physical connector, referred to as Type-C, will be introduced as well. The connector will be similar in size to the current USB 2.0 micro-B but with a different pin layout. Specifically, it will be a reversible connector that will allow the cable to be plugged into the devices in either direction similar to what Apple did with its Lightning connector. This makes the cable incompatible with the previous connector types directly but it will be designed such that adapters or cables can be used to connect older Type-A, Type-B and micro-B with the new port. The cable and connector design are also designed such that it will be compatible with future higher speed USB standards.