date of April 24 is not the finalized date for Call of Duty 4's Variety Map Pack. Infinity Ward's Fourzerotwo, on his personal blog, has divulged that the new downloadable content for the PSN is "taking a bit longer than expected."
Essentially, all the logistics for the DLC have been worked out, and it's just a matter of waiting on an official release date. Fourzerotwo stated, "I got word today that the Variety Map Pack for PS3 has went amazingly well through Certification at Sony and they plan on having it available on the brand spanking new PSN store in the coming weeks."
Fourzerotwo also assures PS3 gamers that the "Play With Infinity Ward" and "Double XP" weekend events will be coming along with the launch of the map pack.