The iMac 2012 release date is set for the end of December for the 27-inch model.
Customers who ordered the iMac will have it shipped to them in 3-4 weeks, according to Apple's website.
Apple originally posted this morning that the new computer would ship in 2-3 weeks, but changed it to 3-4 later on in the day. This will make it tough for those anticipating receiving it before Christmas.
Apple still lists the 21.5-inch models as shipping in 1-3 business days.
These two models are the eighth generation versions of the computer and were first unveiled at an October media event. Apple's Senior Vice President of Worldwide Marketing Phil Schiller called it "the most beautiful iMac we ever made."
The 21.5-inch model can now be ordered through Apple's online store and is also available for purchase at a slew of third-party retailers.
MacConnection is offering the new computer with $20 off and MacMall is selling it for $5 less than normal price. It is also available on Amazon, and Best Buy.
The next-generation iMac's body is 80 percent thinner than the previous model, and features edge-to-edge glass on its display.
Apple also has made the computer 8 lbs. lighter and has given it a FaceTime HD camera in the front, dual microphones, a stereo sound system, an SDXC card slot, 4 USB 3.0 ports, two Thunderbolt ports, and a mini display output with support for DVI, VGA, and dual-link DVI.
The exact measurements for the 21.5-inch are as follows: the computer has a height of 17.7 inches, a width of 20.8 inches, stand depth of 6.9 inches, and will weigh 12.5 pounds.
The measurements for the 27-inch model are 20.3 inches for height, 25.6 inches wide, 8 inches stand depth, and it will weigh 21 pounds.
The 21.5-inch iMac will come with an LED backlit display with 1920 x 1080 resolution, a 2.7GHz quad-core processor, 1TB of storage, 8GB DDR3 memory, NVIDIA GeForce GT graphics processor with 512MB of GDDR5 memory, and it starts at $1,299.
The 27-inch model comes with and LED backlit display with 2560 x 1440 resolution, a 2.9GHz quad-core i5 processor with 6MB L3 cache or 3.2GHz quad-core Intel Core i5 processor with 6MB L3 cache, 1TB hard drive, 8GB of 1600MHz DDR3 memory, a NVIDIA GeForce GTX 660M graphics processor with 512MB of GDDR5 memory, and it starts at $1,799.