Teased just recently, developer XLGAMES confirmed that the upcoming library dungeon will be 1 of the core content found in the version 1.0 update, scheduled for January 2014. There is a long story behind this magical place about wizards and a secret door as well.
The whole area is apparently divided into 4 different areas, including levels 1 to 3 and a lobby. Each level has a different theme and environment design to suit its purpose. For example, there will be more greenery at level 2 as research on plants and animals is carried out.
Other than having unique level designs, there are new monsters which will fit in as well, which can be seen below. The new NPC, an Elf wizard, will apparently be the main antagonist in 1.0 and players will not fight him for now (to be confirmed) . The next set of news will be arriving next week.