It doesn’t look like many people get very excited about the new Nikon SB-910, except Joe McNally of course, who shot the images that came with the product announcement.
The guys at Nikon Rumors have a quick rundown of the differences between SB-900 and SB-910. There aren’t many improvements that are truly exciting. The biggest improvement is perhaps the better thermal management circuit on the SB-910. The other improvements that are worth mentioning are the new dedicated menu button and the hard plastic filters for fluorescent and incandescent color correction. You can check out the specs for both: SB-900 and SB-910.
Are you upgrading?