Guess what we've got

No longer surprised. Next thing you know, they'll add an additional '2' slots for the hammer, but wait! It's going to be with a new CS item called "Heavenly Hammer of Judgment" or some crap, and it's 7k per hammer! And you can only use the hammers after you bought 2 regular hammers to hammer your equipment!

So then your equipment will have 9 slots + additional 4 slots (with hammer) = 13 slots.

This is my prediction for gMS.

Or a Supreme Heavenly Hammer of Judgment that keeps adding an unlimited amount of slots.