What would be interacting is an electron like environment with a pared down JS/CSS engine which only let "modern JS/CSS" (maybe something like Servo). It can be optimized for that, and you don't really have to render electron apps from the 90s anyways.
Another idea is that when wasm will be able to interface with DOM, you'd be able to write GUI code in any language which compiles to wasm. So you won't _need_ Rust (or Go, or Haskell, or D, or your up and coming toy language) bindings for win32, Qt, GTK, etc. Just waste a few hundred megs (only partially /s) and you've got a full ui.
MS seems to be on the way to support PWA directly in Win 10. If other systems would do this as well we won't have to ship a full runtime like Electron.
Another idea is that when wasm will be able to interface with DOM, you'd be able to write GUI code in any language which compiles to wasm. So you won't _need_ Rust (or Go, or Haskell, or D, or your up and coming toy language) bindings for win32, Qt, GTK, etc. Just waste a few hundred megs (only partially /s) and you've got a full ui.