I had figured this was always just one of those rough edges that was going to get smoothed out after the beta phase, but it seems as though the GM release exhibits the same poor behavior--namely a blank profiles list in the "Print" pane.
I have numerous output profiles stored in appropriate locations on my OS X machine, and Photoshop (and every other ColorSync savvy application) finds them just fine. Lightroom however gives me no choice other than "Managed by Printer" regardless of whether I move the profiles to the user, local or system domains. I can choose "Other..." but that just opens up a sheet with an empty list and a set of "OK" and "Cancel" buttons. I cannot drag files into this list, so I have no idea how it's meant to be populated.
I fully realize that the last three tabs after "Develop" in the interface are little more than code-bloating afterthoughts and that serious printing work should be done elsewhere, but this still seems like something that's horribly broken.
I'm having no problem. My profiles are not under 'users' but under the main Library>Colorsync folder. I turned on a printer, chose an image and then chose 'other' under the print module. You should see a list of your profiles so check boxes next to the profiles you wish to have listed.