The iMac 2012 that was announced by Phil Schiller at the iPad Mini event might be facing problems with the new welding technology by Apple for a thinner display. This will cause Apple to delay their productions and the public might not be able to get their hands on the new iMac before 2013 as promised by Apple. The Apple stores still remained silent on this rumor, and the delivery dates of the new iMac were unchanged- 21.5" (November), 27" (December). I will be posting new updates on my site as soon as more information surfaces on the net!
