Bethesda has announced on their official blog that release dates have been set for the Skyrim add on content Dragonborn, Hearthfire and Dawnguard in North America on the PSN. The are currently working on certification with Sony Europe for release in other territories.
The official release dates are Tuesday, February 12th for Dragonborn, Tuesday, February 19th for Hearthfire, and Tuesday, February 26th for Dawnguard. All of the add-ons will be set at a sale price of 50% off during the first week of release.
Bethesda has promised to keep us posted on when the DLCs will be available in Europe.