Missed an important paragraph...
THOR #1, written by Jason Aaron with art by Mike Del Mundo, sees the start of a new mission for the God of Thunder. The artifacts of Asgard have been scattered across the Earth, and to reclaim them, Thor will have to face some ugly truths…Like the production cost of hundreds of new hammers
! And he’ll need every last one of them if he’s going to stop the unstoppable when none other than the Juggernaut joins the fray.
The greater the number of Mjolnirs, the less unique and interesting Thor becomes. I guess you could say the more Thors there are, too, if you see the world the same way Aaron does.
I guess he's trying to bring his "Thors" mini-series dynamic into the 616 (or whatever it is now).