No upgrade for Surface 4 (yet).
The eight biggest announcements from today’s Microsoft event | The Verge
"Windows VR headsets: In addition to the HoloLens platform, Microsoft announced its first foray into virtual reality with VR headsets for Windows 10. The headsets will start at $299 and run the same Windows Holographic platform as the HoloLens. While no concrete release date has been announced yet, Microsoft did say that HP, Dell, Lenovo, Asus, and Acer will all be making headsets."
Microsoft Surface Studio Release Date, Price and Specs - CNET
28" touchscreen, i7, $3000