Peter Robinson recently reported on the status of the 64Bit ARM Architecture (aarch64) for Fedora 21. The progress in userspace appears to be progressing nicely, with the aarch64 architecture having nearly 15 000 packages in Fedora built against it, and people testing packages like libguestfs out on ARM64 devices.
On the hardware side of things, Peter also recently blogged about some of the ARM hardware support that the newly released 3.16 Linux kernel will provide, including support for the NVIDIA Jetson TK1, Samsung EXYNOS, Qualcomm MSM 8×60, 8960 and 8974, APM X-GENE, and AMD Seattle. He also reports that the graphics driver support for ARM systems is also improving with nouveau, freedreno and etnaviv all possibly being supported on some specific ARM devices.