Right now, the Vita TV has only been announced for Japan, China and South Korea, and that's a damn shame, at least for those of us over in the west. I was able to test out the little box's two main functions (big-screen Vita games and PS4 Remote Play) during last week's Tokyo Game Show kerfuffle, and the (approximately) $100 device did exactly what it says on the tin.
My multiplayer Soul Sacrifice Delta session involved one Vita TV and three of the new Vita PCH-2000s, all networked together without any obvious complications. The game controlled well despite being co-opted onto a DualShock 3, ran smoothly and looked surprisingly good on the big screen. In fact, my repeated deaths at the hands of my own incompetence were the only discouraging part of the demonstration.
The Vita TV's PlayStation 4 Remote Play functionality also works surprisingly well from a mechanical standpoint, and I can totally see owning a Vita TV as a PS4-centric media extender for a bedroom or office. There was no perceptible input lag and Knack ran smooth as a whistle, though it's worth pointing out that my test was under optimal conditions – real-world mileage likely varies. Still, what I saw of the Vita TV was very promising overall.
Sony PlayStation TV