Riot games announced that for the Pre-season they will change how runes work and get rid of IP for blue essence. First the runes are getting reworked, they are going to be separated into 5 section each with a “unique” keystone. You will also be able to pick and change the new runes during champion select. For the new season IP and blue essence will be merged into one currency. In the video Riot released they explain that they would refund the IP people used for runes and rune pages bought before 2015; they would be refunded as blue essence. Also for people who used RP to buy rune pages they would receive an Epic Mystery Skin.
For more details: League of Legends changes
For details on the new runes: Runes Rework