There is actually tons of homebrew development going on for the Atari 2600 - it just doesn't get much coverage. I would love to cover most of it but time becomes a factor at that point (figuring out what projects are still going, which are effectively dead, etc).
Have you seen the Mortal Kombat and Street Fighter II ports to the Atari 2600 homebrew devs have created?
RE: 2600 Chess Homebrew Work in Progress