Customers who order one of the new ultra-thin 27-inch iMacs will now have to wait until January to receive them. As picked up by 9to5Mac, Apple’s (AAPL) online stores in the U.S. and Canada show a January ship-time for the large-screened iMac. Apple announced on November 30th that the 27-inch iMac would ship in the next “3-4 weeks.” Obviously, if the new ship times are accurate, the high-end iMacs that start at $1,799 and includes a 2.9GHz quad-core Intel Core i5 processor, 8GB of RAM, 1TB hard drive and an NVIDIA GeForce GTX 660M GPU won’t arrive until the new year. 9to5Mac says shipments might not arrive until the end of January. It’s been reported that difficulties in the manufacturing process are to blame for the iMac’s delay.