The changes corralled by Intel's Rafael Wysocki for the ACPI+PM area of Linux 3.17 include an ACPICA update to bring ACPI 5.1 support, potentially faster hibernation, and basic work towards ACPI on ARM support. The faster hibernation is via using radix trees for storing memory bitmaps.
This pull also has ACPI video updates, various ACPI button fixes, CPUfreq fixes, and other updates. Another prominent change is the faster and more power efficient fix for the CPUfreq on-demand governor.
The full listing of ACPI and power management changes for Linux 3.17 can be found via this mailing list post.