Are the orientations of spin-axes and binary/planetary orbits random or is there any relationship with the Galactic plane? In an answer to another question, a claim has been made that orbit/spin orientations are random (at least within our own Galaxy), except perhaps towards the Galactic centre.
I have dabbled in this area before ( http://adsabs.harvard.edu/abs/2010MNRAS.402.1380J ) and there is a recent paper by Rees & Zijlstra (2013) that suggests planetary nebulae in the Galactic bulge with bipolar morphologies have an alignment with the Galactic plane at 3.7 sigma significance. The hypothesis is that this is due to an alignment of the orbital axes of their parent binary systems, such that the orbital planes of the binary systems are perpendicular to the Galactic plane.
My question: Is there any other evidence for such alignments in other classes of source in the bulge or elsewhere in the Galaxy? Or are there any studies that comprehensively show that angular momentum vectors (spin or orbital) are randomly aligned?
 A: In general the planes of solar systems are not aligned with the plane of the Galaxy, but are oriented in all different directions. The size of a solar system is so much smaller than the size of the Galaxy, that the Galaxy's structure has no impact on the orientation of a solar system. What determines their orientations is the direction of the angular momentum that the system had when it formed, and that's pretty much random.
For instance, our own solar system is tipped by about 63 degrees with respect to the plane of the galaxy.
Recent numerical simulations of the star formation process (Bate,
Bonnell & Bromm , (2002) MNRAS, 332, 705
& (2003) MNRAS, 339, 577; Bate M. R., (2009), MNRAS, 392, 590
& (2009) MNRAS, 392, 1383) have considered the formation of stars within clusters,
starting with initial turbulent conditions for the gas which are designed
to mimic those seen within star-forming molecular clouds.
The picture which results involves turbulent and chaotic motions of
both gas and stars, with disc fragmentation, competitive accretion
and close dynamical interactions all playing a role.
In addition, Bate,  Lodato and  Pringle, Mon. Not. R. Astron. Soc. 401, 1505–1513 (2010),  found that the final stellar rotation axis and disc spin axis can be strongly misaligned,
which may lead to planetary systems
with orbits that are misaligned with the stellar rotation axis
