The USB 3.0 Standard A connector's an elegant solution to the problem of cramming five extra lines into a plug-socket assembly designed to take four. The Standard B arrangement - that more square socket usually found on printers - isn't. The USB 3.0-specific pins have been added in a bulge on top of the USB 2.0 connector, so USB 3.0 Standard B sockets will take USB 2.0 versions, but not the other way round - though there'll surely be plenty of adaptor cables on the market.

SuperSpeed's Standard B port pair
Incidentally, there's a variant of USB 3.0 Standard B that adds a couple of extra power and ground lines to the USB 2.0 part of the plug.
When it comes to micro connectors - there's no Mini USB 3.0 as yet - it gets rather messy. It's perhaps bad enough sticking a tiny, USB 3.0-specific plug alongside the slightly larger USB 2.0 connector, but to make matters worse, there are three version of this arrangement: A, B and AB. We hope mobile device makers - for whom the micro ports were created - will adopt the Micro-AB port since that's able to take any of the USB 3.0 and 2.0 plugs that are likely to come its way.


USB 3.0 Micro B (top) and Micro AB/A
COMMENTS
@ Simon Ward & unexpected Bill
They should follow unreal tournaments announcements
I think it should go Monster Speed followed by Godlike
By the time USB 3.0 ports are to be found in netbooks, they'll be running Windows 7 anyway -NOT!
Windows 7 will not run on Netbooks - MS say Netbooks dont exist - especially the really fast ones running arm chips!
Whatever it is trying to be I'm fairly sure wireless is a much more sensible way to go - nothing new to do there - I don't want cables FULL STOP.
@Eddy Ito: connector standards
I think the reason for the backwards compatible connector is not for devices but for hosts.
Suppose USB3 has different connectors and suppose you are an OEM designing a netbook. There is only room for three ports. What combination do you choose? On one end of the spectrum will be power users who want to plug in loads of USB3 devices, and have hubs and adapters for any legacy USB2 devices, at the other end is the road warrior who has left his USB2 to 3 adapters at home and wants to plug in a USB2 mouse, thumb drive and printer.
With backward compatible connectors you don't have that dilemma. All the ports can be USB3 compatible (if the chipset allows it) and everyone is happy.
@Simon Ward
Regarding "What are they going to call USB4.0? 'Ludicrous Speed'?"
How about "On Speed"?
The only thing I want.
Is for a return to the original ethos of plug-and-play (and-unplug) and not what we have at the moment of plug-and-play then arse-about-stopping-the-device-waiting-a-bit-for-Windows-to-do-it's-thing-and-tell-you-it's-stopped-and-THEN-unplug.
It's not a lot to ask is it?
