Apple Insider posted today a great review regarding the new Apple 27" big screen iMac. The full review can be found here.
Some of the key features for the new model is the fact that iMac comes standard with a wireless keyboard and the new Magic Mouse. Of course there are a lot more, like the fact that the 27" display is equipped with LED backlighting, to push more light through the pixels to achieve the best picture possible. The new 21.5" iMac features 1920-by-1080 HD resolution and the 27" model has a 2560-by-1440 resolution. That’s 78 percent more pixels than the 21.5-inch iMac.

Be sure to read the full review on Apple Insider. You can also check this beautiful piece of hardware at it's official page on the Apple website.