According to DigiTimes, Apple planned to announce new iMacs, a new 13-inch MacBook Pro with Retina Display, and the much-rumored iPad mini in September, but delays caused by insufficient production of displays that meet quality standards have forced Apple to change the launch date to October.
We expect to see new iMacs and a 13-inch MacBook Pro with Retina Display sometime this year; an iPad mini may also be in the pipeline, or it may never be more than wishful thinking. The real news here is DigiTimes' suspicion that retina display yields are the cause of the delay. While the 13-inch MacBook Pro and the iPad mini would certainly use a retina display, I don't expect to see a retina display in an iMac, at least at the current display sizes, anytime soon.
DigiTimes has a mixed reputation for the accuracy of its Apple rumors, so I think we'll have to wait for Apple to send out press invitations to find out what's really coming, and when.