I found this on 4chan, it's 99,9999% fake (well, it's 4chan)
Hmm, though it's suspicious that no news came from anywhere else, it would honestly be rather difficult to fake something of the sort. That drawing style looks like Miura's, and the typography is that of YA.
Also, to give some details, this image says that a new series comprised of 6 episodes (the first of which would be 44 pages, with a color page) will be published in one run, and that said series depicts the world 100 million years after
the current story. In other words, it seems to be a side-story to Berserk more than something totally new. EDIT:
Looking at it again, I doubt the new series takes place in Berserk's world, otherwise they'd have said so explicitly instead of stating it's "all new". Very interesting nevertheless.
From what's on the page, the title could be "Gigantomachia" (referring to the battle between the Olympians and the giants in Greek mythology).