The following solution by Mike is a great method for creating a universal app, with ARMV6, ARMV7, & ARMV7s.
However the crash reports do not work with symbolicatecrash regardless of whether I use the dSYM from Release_armv6-iphoneos or release-iphoneos. I have tried symbolicatecrash from 4.5 and 4.3. Has anyone found a way to get this to work?