Heya,
In Fedora 20, we'll be using BlueZ 5.x to manage Bluetooth devices.
Bluez5 uses a D-Bus API that's not compatible with Bluez4[1] and as such, management applications and a number of libraries and daemons will need to be ported.
For GNOME 3.10 (due September 2013), Gustavo Padovan and I are going to be porting gnome-bluetooth, NetworkManager and PulseAudio to BlueZ5. Packages for BlueZ5 will be available as soon as we figure out how to integrate a few downstream features that were in the Fedora packages.
Bluez4 and Bluez5 are not parallel-installable, and incompatible, so other applications relying on Bluez4 will need to be ported by their respective maintainers.
Cheers
[1]: http://www.bluez.org/bluez-5-api-introduction-and-porting-guide/ and http://lwn.net/Articles/531133/