Before anyone wonders too much about it, the USB Implementers Forum (USB-IF) hasn't actually said anything conclusive about a successor to USB 3.0 yet.
It is obvious that USB 4.0 will eventually be developed though, which both clashes and fits the expectations of Global Information Inc (GII).
GII expects a massive increase in the spread of the USB 3.0 SuperSpeed interface, one that will take place over the course of the next four years.
Long story short, the number of USB 3.0-connected devices will grow by a factor of five by 2016, or so the market research firm believes.
The standard had a bit of a rocky start, but the initial weak adoption is completely owed to Intel and AMD for not including support for the technology in their chipsets for months.
With that issue long past, USB 3.0 can only take over where USB 2.0 left off, and quickly at that.
Shipments of USB 2.0 have reached their peak this year. From 2013 onwards, only some will be preserved, while the rest will move on to the next stage.
This is understandable, as there are some low-end applications and devices that will never need the 5 Gbps transfer rate of SuperSpeed, just like, even today, there are USB 1.1 devices on the market.
Mice are one of the most obvious examples. Even in the case of those models with onboard memory, adjustable DPI settings, button profiles and macros, etc., there is no need for anything beyond USB 2.0, since the connection already provides more energy and data speed than necessary.
The same can be said for keyboards, although the idea of including LCD displays in them, as well as touchpads with full Windows 8 gesture support or whatever else, might cause USB 3.0 to catch on with them in the future.
500% Increase in 4 Years Predicted for USB 3.0 Market
The universal serial bus standard will go a long way before USB 4.0 arrives
... so hot right now