Sony FE 400mm f/2.8 GM OSS Lens is a super telephoto prime lens, the US Price is $11,998, now available for pre-order at B&H Photo Video,Adorama, Amazon,Focus Camera, will be shipping in September, 2018.
Here is another interview with Sony manager Kenji Tanaka, taking about the Sony’s plans in 2019 and Sony’s mirrorless competitors. According to the interview, Sony manager said they can make f/1.0 prime lenses, but it would not make business sense, instead, they are more likely to make f/1.2 prime lenses. And Sony manager also confirmed they will make a new super telephoto prime lenses similar to Sony FE 400mm f/2.8 GM lens(B&H,Adorama, Amazon,Focus Camera).
In a recently interview with Sony manager Kenji Tanaka by dpreview at CP+ Show 2018 in Japan. He talks about recently announced full frame mirrorless camera Sony a7 III (B&H/Adorama/Amazon), and upcoming FE 400mm f/2.8 GM OSS Lens, a9, weather sealing, APS-C mirrorless cameras, firmware updates and more, you can see the detail below: