For the most part, ESL/DreamHack did not announce any major changes to the format of DreamHack Masters. Instead, they explained why they've decided to largely maintain the format from DH Masters Summer, and how they will try to improve upon it.
For instance, the round-robin group stages in Master EU and NA will continue to be played over the course of several weeks, but the broadcast will include more graphics and updates to allow fans to better follow the progress of the groups on a match-to-match basis.
Many smaller changes were announced across the board, including shorter break times between each regional tournament, fairer seeding in the season finals, adjustments to the cross-regional server selection policy, and increased moderation of Twitch chat (read official announcement for full list of changes).
The schedule for DreamHack Masters Fall has also been announced, with the tournament scheduled to take place between August 26th and September 20th.