Space News has an article about planning for a second, seven year extended Cassini mission that would follow the end of the current extended mission (giving Cassini a total of about 13 years of scientific exploration at Saturn and Titan). A number of options are being examined. The current extended mission is costing $80M per year, and the goal was to cut that in half for the second extended mission. That apparently was too little to safely fly Cassini, so mission planners are presenting NASA with a range of options where NASA can pick the amount of science it wants done and pay accordingly.
The Space News article will only be available for a week, I believe. This presentation gives lots of detail on various options including a possible end of mission where Cassini flies inside the rings and just above the atmosphere to provide high resolution gravity and magnetosphere measurements. This mission end would replicate at Saturn a good portion of the science that will be done by Juno at Jupiter. (Cassini can't do Juno's deep atmospheric structure and composition sounding because it lacks a microwave radiometer that Juno will have.)