I had this problem on Ubuntu Gnome 3.10 Final beta. The bug was also present on Fedora 20 Alpha 1 (Gnome 3.10). The only issue seems to be that the pin information is not being retrieved by bluetooth-wizard.
To get around the issue, I set my keyboard (MS Sculpt Mobile) to discovery mode, ran "sudo hcidump -at" in a terminal, then opened bluetooth-wizard, attempted to connect to the keyboard, checked for the pin in the terminal as reported by hcidump, entered that into the keyboard and pressed "enter", and bluetooth-wizard completed the set up.
I had this problem on Ubuntu Gnome 3.10 Final beta. The bug was also present on Fedora 20 Alpha 1 (Gnome 3.10). The only issue seems to be that the pin information is not being retrieved by bluetooth-wizard.
To get around the issue, I set my keyboard (MS Sculpt Mobile) to discovery mode, ran "sudo hcidump -at" in a terminal, then opened bluetooth-wizard, attempted to connect to the keyboard, checked for the pin in the terminal as reported by hcidump, entered that into the keyboard and pressed "enter", and bluetooth-wizard completed the set up.