The launch is still some time away as NVIDIA is seemingly waiting for the right launch window. The firm will first let AMD launch its high-end Radeon R9 300 series a month or two from now and the current plan is to launch the GeForce GTX 980 Ti sometime around September, which would give add-in board (AIB) partners plenty of time to create versions with custom PCB and custom coolers.
However, since the card is already finished there's also the possibility that NVIDIA might try to crash the launch party of AMD's Radeon R9 390 series.
According to the latest rumors, the GeForce GTX 980 Ti is based on the GM200 with all 3072 CUDA cores intact, just like the GeForce GTX Titan X. One of the big differences though is that the memory amount is halved to 6GB GDDR5 to pull the GM200 to a lower price range.