(Image Caption: The Apple Thunderbolt Display connected to a MacBook Air. A Thunderbolt RAID array (the Promise Pegasus R6, right), and a FireWire 800 RAID array (the Promise SmartStor DS4600, left), are connected to the display.)
The $999 Thunderbolt Display's specifications are impressive, but not much different from Apple's ( Macworld rated 3.5 out of 5 mice ) released last year. Both feature LED backlit displays with a resolution of 2560-by-1440 pixels, the same brightness rating of 375 cd/m2, MagSafe power connector for charging a laptop, and three USB 2.0 ports. The Thunderbolt Display has a FaceTime HD camera, while the Cinema Display has an iSight camera.
(Image Caption: The Thunderbolt Display (right foreground) has more connectivity options than the Cinema Display (left background).)
What's new--and what's really exciting--is the addition of a FireWire 800 port, a gigabit ethernet port, and a (of course) Thunderbolt port to the back of the display. You get all of these extra ports, and at the same time, you have fewer cables to string to your Mac--the Mini DisplayPort and USB 2.0 connector cables on the Cinema Display have been replaced with a single Thunderbolt connection.
(Image Caption: The Thunderbolt and MagSafe cables (front) from the Thunderbolt Display. In the background are the MagSafe, Mini DisplayPort, and USB connectors from the Apple 27-inch Cinema Display.) If you, say, have a FireWire 800 hard drive, you can connect it to the Thunderbolt Display. That hard drive is then connected to your Mac via Thunderbolt. Ethernet and USB work in a similar way.