The USB Promoter Group -- an association comprising Apple, HP, Intel, Microsoft, Renesas, ST Microelectronics and Texas Instruments -- today announced the pending USB4 specification, slated to deliver 40-gigabit-per-second throughput and support for host-based algorithms to more efficiently handle data operations.
USB4 will use the sameconnector we've grown used to and still require specific cables to obtain the maximum 40Gbps (5,000 MBps) throughput; with standard cables, it goes up to 20Gbps (2,500MBps). It will still be able to communicate with devices as far back as USB 2.0, too.
From a user standpoint, you probably won't notice much difference, with possibly two exceptions. Because Intel's building TB3 support into its, Windows users won't have to deal with an extra Thunderbolt driver to take advantage of it and developers won't have to rely on one. Plus, because of that and its backward compatibility, and the fact that Intel gave the Thunderbolt protocols to the USB Promoter Group royalty-free, expect to see USB4 adopted more widely than the remarkably similar USB-C 3.1 Gen 2 (aka ).
Of course, it takes a while to get from "specification" to "implementation," so it could be a while until it takes off. Hardware with Intel's Ice Lake chips isn't hitting the stores until the end of 2019 the earliest, and it probably will be at least another six months minimum before a significant number of systems have incorporated it.