Personally, I'd be surprised if Go replaced Java in academic contexts. Java has inertia, marketability, better cross-platform support, and bundled GUI stuff. That said, were I teaching a general programming and/or data structures course, I'd probably strongly consider using Go. It is possible and not unreasonable for students to read and understand the whole Go spec. The language is simple and orthogonal enough that I think students could start seeing past the language and to the tasks at hand rather quickly.