One idea I had: increasing point gains similar to the buff found in ICC (and DS I guess?). The first week you get x amount of points (very small amount). The 2nd week you get more points per boss than the first week (and so on). By the end of the 'season' you'd be point saturated but that can be solved with a gold conversion and a reset. I suppose this would not only apply to vp gain but also cap. Just a rough idea.