TPCast's system was only available via Vive’s Chinese website at first, but now HTC says that it'll be available globally in Q2 this year, with pre-orders opening up sometime later this quarter.
And you'll probably want to order as soon as you can: although US$249 might seem pretty steep for an attachment for an already-expensive headset that plugs into a surely-pricey PC, the initial Chinese release of the TPCast immediately sold out. Like, in minutes.
We're not surprised. Removing the constant tug of the cables on the back of your head could make an already amazing VR experience even more immersive. And, it's a much neater solution than the PC backpacks that were a hastily constructed solution to the problem.
Virtual and actual fingers crossed for that release being sooner in Q2 rather than later.