I know that one thing that would be incredibly useful for fantasy baseball players would be to use fangraphs' custom teams interface to allow users to see customizable matchup data for their players. Other sites do this, but they don't use the right data. For example, in Yahoo's fantasy interface, you can see which teams and SPs your players are up against, and on Yahoo's player pages, you can see how an individual player has done against a particular pitcher or team in the past, but these stats have limited value since they're based on tiny sample sizes. Fangraphs could provide matchup data that would actually be much more useful, including:
1) Opponent team
2) Opponent team's wOBA by opposing pitcher handedness
3) Ballpark factor (by pitcher handedness)
1) Opposing pitcher (with handedness)
2) Opposing pitcher's FIP/xFIP (by hitter handedness)
3) Ballpark factor (by hitter handedness)
I think fangraphs already has all of this data available, so it'd mostly be a matter of setting up the interface. Is there any possibility that this might happen in the future?