Detailed at FedoraProject.org is the proposed Python 3 change for Fedora so that it becomes the default implementation of the popular scripting language over Python 2. Python 3 hasn't been made the default because some important packages are only supported by Python 2, including the package manager, the minimal buildroot, etc.
While Python 3 isn't the default, it is installable on Fedora Linux. With this proposed change, Python 3 would become the only implementation in the minimal buildroot and on the LiveCD, the package manager would work fine with Python 3, and the Anaconda installer along with cloud-init would be compatible with Python 3. Making all the changes for code compatibility is expected to take the Fedora 21 and Fedora 22 development cycles.
This work was approved today during the Fedora Engineering & Steering Committee meeting, per the meeting minutes. "AGREED: Feature is approved, provided that the contingency plan is updated with permitting a mixed environment of py2/py3...FESCo strongly advises prioritizing this work on those packages that appear in the minimal and cloud images first."