The RIFS-ES Scheduling V1 release was announced over the weekend on the Linux kernel mailing list.
The RIFS-ES scheduling design utilizes the design of the System V scheduler and can be made interactive with reportedly better/smoother Linux desktop experience. As said by Chen, a RIFS-ES developer, "CFS is good with its beautiful design. But in my opinion I think the sleeper feature will destroy the beautiful design."
A few benchmark results comparing RIFS-ES and CFS can be found in this follow-up LKML message.
Additional information on the RIFS-ES interactivity favor scheduler can be found via the Google Code site. At the moment there are patches against this first release to apply against the Linux 3.4 kernel.