We predominantly got split faction plant/treefolk/vampyres, with two solely UD champs. Personally, I rather like the Naria runes, both thematically and in mechanics. De'lim has been burning the forest (as forest fires are natural and strong things come of it), the Nefari have been burning the forest (because screw the forest), and so nature has responded with these things. They work better, I find, with FF KF battlegroups (and make the Mysterious Hooded Elf' a little more useful too) than they do with FF UD but they can function well enough. One mustn't forget that they, as Vampyres, can consume blood balls.
I am not an UD player but I am really curious to see what Naria does to vampyre builds. It has been a long time since they got this many runes in a short amount of time.
Well, having experimented a little bit with a FW/KF battlegroup centered around vampyres, I will say that Greater Vampirism does make the Naria Flamewillow's Conduit: HP slightly more useful. I imagine in a FW/UD vampyre bg, the Globe of Deception would get a great deal of use, but that is no different than things were before this expansion.