Windows 7 64-bit, GTX 580
Broken: BuildBot 2.73.1 8a28895 (Jan. 3rd, 2015), also BuildBot 2.72.2 5c6e33 (Nov. 11th, 2014)
Worked: BuildBot 2.71 b49e6d0 (Jun. 19th, 2014)
Short description of error
If I set a shrinkwrap constraint on a bone and set it to project in the +Z direction in pose space (the armature object's local space, if I'm not mistaken,) it will instead be projected to the target in the +Z direction in the bone's local space.
Exact steps for others to reproduce the error
Observe the behavior of the three bones in the same armature - all are meant to be projected to the landscape above, but the one whose local axes aren't aligned with the armature object's axes isn't projected up when the constraint is set to project it in the pose space's +Z direction. It is instead projected sideways, in the +Z direction in the bone's local space.