The Eidolon is no longer actively used in game. The model itself is still current but does not have V5++ shaders. Currently there are no known owners of the ship. According to EVE lore, the Jove are now extremely sparse, thus Eidolons are extremely few and far between.
There have been very few encounters with Eidolons in Eve's history, most of them were piloted by CCP capsuleers. The latest known encounter with one of these was piloted by CCP GM "The Doctor", in YC 114.