At the company’s media event on Tuesday, Apple unveiled a completely redesigned iMac in front of a packed audience sitting in San Jose’s luxurious California Theatre. This has been the first major iMac redesign in roughly three years.

“Today is a big day for the Mac,” said Phil Schiller, Apple’s senior VP of marketing. “The iMac is the best all-in-one computer in the industry. As you’ve heard, it’s actually the No. 1 desktop model in the US. Many think of it as the flagship of the Mac product line.”

Schiller showed the evolution of the iMac shortly before unveiling the brand-new model and bringing it on stage.

The new iMac, at its very thinnest point (the edge), is just 5 mm thin, which is 80 percent thinner than the previous generation. The computer itself is also eight pounds lighter than the previous generation.

“This is so thin we wanted to do something even more with it – the way this is welded is called friction stir welding.”

By laminating the display directly to the glass, Apple was able to remove all air gaps from the computer, making the entire display system 45 percent thinner. By removing the optical drive and reeingereering the internal components, Apple was able to make the new iMac “amazingly thin.”

The new iMac comes in two sizes with ISP panels for great viewing angles: the 21.5-inch model features a 1920 x 1080 resolution, while the 27-inch iMac features a 2560 x 1440 resolution. A new process called plasma deposition allowed the screen to achieve 75 percent less reflection than the previous iMac generation.

The 2012 iMac features two speakers on the bottom sides of the “chin,” as well as a 720pHD FaceTime camera, as well as dual microphones on the top.

As far as storage, the iMac contains up to 3TB of storage with a Core i5 or i7 processor, but Apple customers must choose what kind of drive they want.

“Customers can choose what they want, a hard drive for storage, or an SSD for speed. But we have a new option,” Schiller said. “It's called the Apple Fusion Drive."

Apple’s new Fusion Drive contains 128 GB of flash storage with 1TB or 3TB HDD, which is fused into a single volume. With access to storage, the new Fusion Drive performs almost as well as Flash, but it keeps documents significantly more secure on the HDD.

“Apple has some logic which figures out which apps you use the most and will shift those to the SDD,” Schiller explained.

The 21-inch iMac features a 2.7GHz quad-core i5 processor with 8GB of RAM, a GeForce GT 640M and 1TB of HDD. This model will begin shipping in November.

The 27-inch model features a 2.9GHz quad-core i5 processor, 8GB of RAM, a GeForce GTX 660M, and a 1TB HDD. This model will cost $1,799, and will release in December.

Even though the iMac’s arrival was a surprise to many that were just expecting a new iPad Mini and maybe an update on iBooks, a few had previously predicted Apple would unveil such a computer.

On Oct. 14, a user, who claimed to have a brother-in-law working in the factory building the new Mac computers, posted cell phone images of an iMac with a redesigned screen on the site’s forum, calling the “teardrop-shaped” design “revolutionary.” The poster compared the iMac to a drop of water with “tetragonal elements” -- even though the new computer reportedly still has that trademark “chin” below the display -- and added that, from side to side, you “almost cannot see the new iMac’s thickness.”

One of the most important aspects of the new iMac noted by the user was its “expensive” display. According to the post, the new iMac’s display featured a “very pretty special glass glued directly” to the computer, rather than in past iterations of the iMac, where the display was manufactured separately from the machine.

Following the posting, the new iMac’s design was verified by the repair experts at iFixit, who said the internals shown in the photos are similar to the current iMac with the plastic radio-transparent circle on the back.

It was uncertain whether or not the 2012 iMac would feature a Retina Display, but given that Apple would’ve had to bump the pixel density of the 21.5-inch model to 3840x2160, but a Retina Display on a 27-inch iMac would require a 5120x2880 pixel resolution. This would be an absolutely monstrous display, but it could create more problems than benefits, especially when it comes to overheating or even handling the intensely dense resolution on a daily basis.

According to an old benchmark from Geekbench makers Primate Labs, the new iMac, described as “iMac 13,2” internally, was going to run on a 3.4 GHz Core i7-3770 quad-core processor with 4GB of 1600 MHz RAM and run on the OS X Mountain Lion operating system. In August, Kuo released his own product launch schedule, pegging the release of a new iMac in mid-October.