From the Rockstar Blog:

Due to a last minute game submission request from Sony Computer Entertainment Europe to edit some of the in-game Liberty City radio station, television, and internet content – we are forced to delay the worldwide release of Grand Theft Auto: Episodes from Liberty City for both PlayStation 3 and PC for an extra two weeks.

The new release date for Episodes from Liberty City - and the two downloadable episodes The Lost and Damned and The Ballad of Gay Tony - on those platforms is now April 13th in North America and April 16th in Europe. This new date will enable us to rectify these changes for Sony Europe, and still allow for a level playing field for all of the Grand Theft Auto fans that have been waiting patiently for this release. In the meantime, we’re moving full speed ahead towards the new game release date. On that note – please be aware that the Grand Theft Auto IV PlayStation 3 leaderboards at Rockstar Games Social Club will be down for maintenance for one week starting March 22nd as we work on their re-launch in support of Episodes from Liberty City.