It won't be the DLC. It's a patch, that will probably add kill cams for magic or something. When people have reported the tweet, they report it as dlc, when the tweet says content.
The reason this is an important issue, is how Pete Hines defined the words add-on content in the early days of this crazy story. Any patch and the content it contains (ie the kill cams and fighting from horseback) is considered new content in his explanation. The reason he defined the add-on content from the back of the box, is when ps3 fans were attempting to rally together to sue bethesda for false advertising.
Next up, The PC isn't missing content, or rather after the 30 day wait, won't be missing the dragonborn dlc. The 360 contract probably referred to the full sized dlc's, instead of the small Hearthfire.
PS3 fans shouldn't get there hopes up. Unless they say that it's the dlc, don't expect it to be the dlc.