Initially released as independent module in 1983, I6 Ravenloft (TSR 9075) for AD&D 1E quickly became a fan favorite. The module followed the story of Count Strahd von Zarovich, a vampire trapped in the lands of Barovia over which he ruled by plaguing the inhabitants with fear and terror. I6 Ravenloft was unique at the time as it used variable locations for key aspects of the story discovered by the use of Tarokka Cards (Tarot Cards).
The second module, I10 House of Gryphon Hill (TSR 9181), released in 1986 used similar mechanics and continued the Gothic Horror style was well received by player base leading to the development of a complete campaign setting Ravenloft: Realm of Terror boxed set (TSR 1053) for AD&D 2E released in 1990.
Recently in 2016, WotC started adapting and resurrecting some of original Ravenloft materials for D&D 5th edition.
We are very interested in bringing Ravenloft to DDO, it's not so much a matter of if, as it is when, So it is a plan that we are absolutely pursuing at this point, to go into Ravenloft. Stay tuned for More information
There can always be things, that lead to changes in our scheduled and that sort of thing, but we are very much interested into going into Ravenloft, at the very least it will be brought up in a producer's letter, that we are working on it currently