I upgraded today from rc1 to -dev, and as a result started getting errors like this:
Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 9020 bytes) in .../public_html/profiles/commerce_kickstart/themes/omega_kickstart/template.php on line 35
So I upped the PHP memory limit to 512M, and corresponding errors occurred. So I upped it to 1 gig, the error went away, but I could no longer even reach the page, I got a 'connection reset' page instead.
In the meanwhile, admin theme pages continued to work.
So I downgraded to the rc1 version of all the themes, and the problems went away.
Just thought I'd let someone know.