We are starting to work on entirely new development for 6.1, but instead of inviting you intrepid leading-edge types to begin using it for production right away (as was the case with the 5.0 / 5.1 transition), we expect to spend a few months exploring a variety of possibilities without the pressure of having to maintain an evolving product in working/maintainable condition. And, since the Conference is coming up in a few months, this would be a good time for developers to propose development ideas to be considered for 6.1 and/or to be researched and then address at the Conference.