This seems to be positioned as a replacement for the 21.5" iMac, and the 27" iMac replacement is yet to come. During the announcement they only ever compared it

This seems to be positioned as a replacement for the 21.5" iMac, and the 27" iMac replacement is yet to come. During the announcement they only ever compared it to the 21.5" model, and it's pretty much a strict upgrade compared to that.