KM, #S, and I have spitballed a path toward addressing the Co-op and Single-Player issue.
If we make it that far, you will be pleased with what we create. Logistically speaking, a lot of what needs to be done is already in progress. I'm brewing the classic maps albeit slowly because it's my hour-a-day hobby, Live and Let Die shows much of the logic can be knocked-out in a LUA script, and that really leaves only the grunt work of making the models, coming up with fun ideas to enhance the gameplay, and adding a few new code chunks.