USB Type-A. USB Type-B. Mini-USB Type-A. Mini-USB Type-B. Micro-USB Type-A. Micro-USB Type-B. That special, ugly variant of micro-USB Type-B you need to use for phones (and some hard drives) with USB 3.0 support.
These are the different types of connectors you have to be aware of to use your current USB-equipped computers, phones, tablets, printers, and whatever other accessories you might have. The USB Implementers Forum (USB-IF) wants to simplify this problem by rallying behind the new Type-C connector, a new specification designed to replace current Type-A and Type-B plugs of all sizes. While we already knew that the USB Type-C connector would be smaller than many existing connectors and that (like Apple's Lightning cables) it would be reversible, we didn't know exactly what it would look like before today..
The renderings released by the USB-IF today are still subject to change, but they show a Type-C connector that looks pretty much like you'd expect. Current cables usually use different Type-A and Type-B plugs on either end out of necessity—most computers use standard-sized Type-A connectors, while phones and cameras need either mini- or micro-sized Type-B connectors on the other end. Type-C will eventually supersede all of them, providing the same type of connector on both computers and phones.
For those of you just joining in, this new connector was outlined by the USB Promoter Group back in December of 2013. The Type-C connector will supposedly be finalized by the middle of this year and available in actual shipping products at some point after that. The connector is described as a "supplement to the USB 3.1 specification," which boosts USB's maximum theoretical throughput to 10Gbps from USB 3.0's 5Gbps.
Current USB protocols and connectors are so widespread that it's difficult to say for sure how long it will take USB Type-C and USB 3.1 to replace them all. Computers with the nearly two-decades-old Type-A plug will be particularly slow to change, meaning that even if phones and tablets are quick to adopt USB Type-C connectors, we'll still be using adapters to connect them to computers and chargers for some time to come.