Confirmed: New Rozen Maiden Manga Series has just started since March 2016 titled: "Rozen Maiden Zero"
Set in Tokyo, during the Taishō Period (July 30th, 1912, to December 25th, 1926), a young maid called Kiku (菊（きく）), goes up into the attic of the mansion she works in one day and discovers a porcelain doll with a key inside a box. The key has a message: "To wind, or not to wind". Winding the key, she awakens the Third Rozen Maiden doll, Suiseiseki from her sleep. Meanwhile, the young master she works for makes contact at the top of the Ryōunkaku (凌雲閣, lit. Cloud-Surpassing Pavilion) with the First Rozen Maiden, Suigintou, who reveals that there is an eighth doll; the "Zeroth" Rozen Maiden".
The first couple of chapters have already been translated into English, and the rest will be following shortly.