Dual Band (concurrent) and Gigabit Ethernet.
Advertised as 750 Mbps it is Dual-Stream (2x2) on the 2.4 Ghz Band and Triple-Stream (3x3) on the 5 Ghz Band. WDR4310 owners should reference the better maintained WDR4300 page. TP-Link TL-WDR4300
You can flash your image using the factory web interface, after this the WDR4310 should behave the same as the WDR4300.
TP-Link TL-WDR4310 Version 1.0 forum thread
U-Boot 1.1.4 modification for routers
Forum member pepe2k made a modification of U-Boot 1.1.4 for Qualcomm Atheros SoCs based devices (the project is still being developed, so new devices and SoCs will be supported in the future). Up to date information, binary images and sources can be found on official GitHub repository.
This modification started from wr703n-uboot-with-web-failsafe project, but supports more devices, all modern web browsers, has a lot of improvements and other modifications (like U-Boot NetConsole, custom commands, overclocking possibilities etc.).