The Apple Store went offline this morning, signalling what looked like the long awaited refresh of the iMac line of desktop computers.

In the past few minutes, Apple has switched the Store live, introducing new quad-core iMac computers, incorporating the new high-speed Thunderbolt technology, FaceTime HD camera and new graphic capabilities.

Priced at $1,199 and upwards, the new iMacs will feature Intel’s Core i5 processors with an option to upgrade to Core i7 processors up to 3.4GHz. New AMD Radeon HD graphics processors will deliver the most powerful graphics ever seen in an all-in-one desktop computer. Intel’s Thunderbolt technology will also be included for the first time in a desktop computer, launching with one port on the 21.5-inch iMac and two on the 27-inch model.

Screen shot 2011 05 03 at 13.48.46 520x337 Apple launches new Quad core iMacs with Thunderbolt technology

The refreshed iMac range is available to buy through the Apple Store and Apple’s retails stores right now, one with a 2.5 GHz quad-core Intel Core i5, AMD Radeon HD 6750M and 500GB hard drive starting at $1,199. The 2.7 GHz quad-core Intel Core i5 model sports an AMD Radeon HD 6770M and 1TB hard drive and costs $1,499.

The 27-inch iMac is available in two models: one with a 2.7 GHz quad-core Intel Core i5, AMD Radeon HD 6770M and 1TB hard drive retailing at $1,699, with a 3.1 GHz quad-core Intel Core i5, AMD Radeon HD 6970M and 1TB hard drive costing $1,999.