Nikon has announced the SB-910 Speedlight, and it looks to be the camera giant's new king of high-end flash units. Replacing the SB-900 from three years ago, the main changes are a variety of usability tweaks, including an improved GUI and operating system. We'll have to get our hands on a unit to see exactly what Nikon means by that, but it should be a welcome revision — you had to dive into some pretty labyrinthine menus to get to the SB-900's many settings. Technically, it doesn't look like much has changed, as the SB-910 retains the same button layout, 17-200mm full-frame zoom range, and guide number of 111.5 feet at 100 ISO. Elsewhere, the unit now has more efficient battery performance, uses hard white balance filters, and there's a new thermal cutout feature which will slow your shooting speed down when things start heating up. It's also managed to gain 5 grams on its predecessor. At $549.99, we're not sure that this will be an essential upgrade for many SB-900 owners, but those waiting for Nikon's latest and greatest should be pretty satisfied when it launches this December. If only it could be joined by that elusive D800...