Eat your heart out, Thunderbolt. The USB 3.0 Promoter Group has announced a "supplement" to the USB 3.0 specification that will raise data rates to 10 Gbps, up from the current maximum of 5 Gbps. 10 Gbps matches the speed of a single Thunderbolt channel, although only in one direction; Thunderbolt offers 10 Gbps of bidirectional bandwidth per channel. With two channels per port, aggregate bandwidth adds up to 40 Gbps.
The new, higher USB data rate will be achieved through "enhanced" cables and connectors. Those cables and connectors will, of course, be compatible with USB 3.0 and 2.0 devices. I'm not seeing many other technical details in the official announcement or the linked documentation—just something about the updated standard using "improved data encoding" to boost both throughput and power efficiency.
In any case, the USB 3.0 Promoter Group says the quicker standard is "targeted for industry review" this quarter and should be completed by the middle of 2013. The first products will presumably show up some time after that. Here's hoping the standard gets its own version number—maybe, say, USB 3.1—to prevent things from getting confusing.
This speed boost might throw a damper on Thunderbolt's already lukewarm adoption. Thunderbolt is still quicker, however, and it has other redeeming qualities, including support for fiber-optic cables and the fact that it combines PCI Express and DisplayPort signals. For example, with just one Thunderbolt data cable connecting it to the host system, Apple's Thunderbolt Display delivers a 2560x1440 image in addition to USB 2.0, FireWire 800, and Gigabit Ethernet connectivity.