We’ve heard about the Lumia 910 a few times in the past, but not much is known about it. One theory suggested that the 910 was just a European version of the Lumia 900. The name has popped up again but we still don’t know any more about it.
The name appears on the device listing for Nokia’s Remote Device Access service. It’s interesting to see the 910 show up again now, because we don’t expect any new devices to come out before WP8. It’s likely that if this device ever sees the light of day it will be an variation on the Lumia 900. Nothing to get excited about.