If you have a recent VMware vSphere installation with a vCenter server in production or in a lab then you will be aware of that the Web Client is the recommended choice for managing the environment and that the well known C# based vSphere Client is considered deprecated or legacy (since version 5.1 already).
However, when you connect to the Web Client of your freshly installed vCenter server for the first time using your favorite Internet browser you will be greeted by a more or less alarming warning. Chrome even warns you that VMware might steal your credit card information ;-) (well, they probably already have that) ... You should really be worried whenever you see this warning on a random Internet site, but you don't need to if it's your company internal vCenter server that you try to access.
So, why do you get this message, and how can you get rid of it?
The October 2014 patch of ESXi 5.5 already got a lot of attention, because it introduced additional Transparent Page Sharing (TPS) management capabilities to prepare for TPS being disabled by default in upcoming ESXi releases. And William Lam pointed out that this patch enables support for the Apple Mac Pro 6,1 ... but there is even more goodness in this patch!
When adding the associated Image Profiles to the VibMatrix I noticed that this bundle includes a new package named xhci-xhci. The related KB2087362 article only includes the standard disclaimer, but no information about what this really means: xHCI stands for Extensible Host Controller Interface, a USB standard that supports USB 3.0 (or SuperSpeed) controllers and devices.
That means with the latest ESXi 5.5 patch you are - for the first time - able to utilize USB Passthrough with USB 3.0 devices!