Some comments in the game's dialogue mention both of these at some point and I did find a map of Murkmire in Orsinium some time ago. I'd say one will probably release this year though and one next year.

Around mid 2017.
Guys... they kinda did say a while back what they intended... 2016 will see thieves guild, dark brotherhood, aaaaaand i think there was something else but i can't pin it now... something we blabbed about for quite a while, anyway.. 2017 will see the later dlcs like the clockwork city or mephala's realm, and all the other cool stuff. well, they'll go around 2 or 3 updates every year. so yea... all that about duels, arenas, barber shop, when they say 'no ETA' they actually mean : "After we do everything, then we start working on it"... wich means, 2018 until you can change that stupid haircut.

They probably have a huge collection of DLC that they're working on all at the same time, and are picking whichever ones are farthest along to focus on for the next launch. We know from the videos and such they've released that there is at least something made for Murkmire, Mephala's Realm, and CLockwork, but we'll never know how much is finalized and how much is "vaporware" until it's all in. I do suspect that they've at least finalized many set pieces, however, since we've seen them in places like Maelstrom Arena. So Things Are Being Done, but we'll have to wait on exact release schedules.