Bethesda has now given solid release dates for the DLC for Skyrim on the PlayStation Network.
According to the Bethesda Blog, the first DLC coming will be Dragonborn on February 12. Next will be Hearthfire the next week on February 19 and finally Dawnguard will arrive on the PSN on February 26.
As stated earlier, the DLC will be 50% off for the first week they are available.