I'm also skeptical about how new these are as well. The model behind them, the Vidente Eldar.. That's roughly Eldar (far)Seer, and I don't know of any new ones on the horizon. If someone can match up the legs to a current farseer, you can see when the greens were actually introduced. Both those do look pretty awesome. The one on the left looks more like a Wych than a Haemonculus though.
EDIT: Upon further review, I looked at all the Farseer figs and no legs match up with those legs. And that model is definitely pewter-looking.. New farseers as well as new dark eldar?
RE-EDIT!: Apparently, that farseer is an older unreleased farseer. I came upon it in the warseer post about this dark eldar picture. They had the farseer's picture and the legs are identical. And its an ugly model. Let's hope that those aren't BS greens.