  We examine entropy production in relativistic U+U collisions on the basis of
a Color Glass Condensate (CGC) type picture as implemented in the
Kharzeev-Levin-Nardi model (KLN). In this framework, we find that the peak
entropy density produced in tip-on-tip U+U collisions is about 30% greater than
that seen in central Au+Au collisions. Although the resulting difference in the
produced charged particle multiplicity between tip-on-tip and side-on-side
collisions is smaller than that predicted by previous Glauber model estimates,
it is still large enough to allow for experimental discrimination between
average orientations of the uranium nuclei. We also point out that in the
saturation/CGC approach the collision geometry plays a more important role than
previously believed, and that the observed centrality dependence of the
produced particle multiplicity per participant in Au+Au collisions can be
qualitatively reproduced even without running coupling effects.
