Even though Bethesda isn't creating any more new content for Skryim, that doesn't mean the publisher isn't keen on providing a compilation of the core game and all its downloadable content.
As has become the norm, a complete edition of Skyrim appears to be on the way based on Polish retailer Ultima's website. Spotted by CVG, the posting indicates Elder Scrolls 5: Skyrim - Legendary Edition will include the main game, plus all three add-ons (Dragonborn, Hearthfire, and Dawnguard).
Bethesda has done similar re-releases for titles like Oblivion, Fallout 3, and Fallout: New Vegas, so it wouldn't be entirely out of the question for the publisher to do the same with Skyrim. More and more companies are reselling titles in this fashion, and there's no harm in getting content to as many people as possible, even if it is just repackaged.
If you haven't already played through 2011's Skyrim, the Legendary Edition appears to be the way to go as it will include a host of additional content. Hopefully Bethesda will make the release official soon, though we can understand if the company is noticeably busier with other announcements.