No, no one knows yet but I can tell you what happened last year. Unofficial dates were circulating around Disney boards by mid-April. The official dates and tickets were released by Disney April 30, the earliest they were ever released.
I would think we will find out April first when they have October calander up.
Whatever days they close early are most likely MNSSHP. I would tenatively plan those days. I know I have been planning on Tuesday the 24th based on last years schedule.