I took delivery over the weekend of the new Apple 27-inch Thunderbolt Display (MC914LL/A, $999) and it's a fine, fine piece of engineering. I replaced the previous generation 27-inch Apple LED Cinema Display (MC007LL/A) with the new Thunderbolt variety and, looking at them from the front, you can't tell the difference.
But you certainly can tell them apart from the rear.
In fact, If you didn't look at the back (or cheat and peak at the cables) Apple's 27-inch displays are virtually indistinguishable. They're both giant 27-inch, 16:9 aspect ratio, glossy, widescreen displays with 2560 x 1440 resolution. They both come equipped with a microphone, speakers and a video camera (the older, an iSight, the newer, a FaceTime HD camera).
Here's the port area on the backplane of the 27-inch LED Display, released in September 2010, with its (comparatively weak) three USB ports.
The 27-inch LED Cinema Display includes a built-in USB hub that uses one of your Mac's USB ports and breaks it out into three on the back of the display. Convenient? No doubt.
Now take a look at the backplane of the new Thunderbolt Display:
In addition to the three USB ports found on the old jive, the new Thunderbolt Display also includes (L to R) a FireWire 800 port, Thunderbolt port and Gigabit Ethernet port. And the best part is that all six ports are powered by the Thunderbolt port on your 2011 Mac. And do take note about the Thunderbolt part as you can't drive the new monitor with non-Thunderbolt (pre-2011) Mac.
The new Thunderbolt Display will be especially tempting for MacBook Air owners because you get to keep both onboard USB ports and you get three more to boot, for a total of five. But it's also great for MacBook Air owners that need Ethernet because you don't have to buy a $29 USB-to-Ethernet dongle (although you'll still need the dongle when you take your Air on the road.)
You can even daisy-chain Thunderbolt monitors together. MacRumors posted a video of it in action but it only works from a MacBook Pro because it has a discreet graphics card (sorry MacBook Air owners).
Arguably the best feature of this wonderful piece of hardware is the cabling setup. It's made for MacBooks. Anyone who has a MacBook and connects it to a desktop monitor, keyboard, mouse and untold other peripherals will attest to what a pain it is to undock/re-dock. This usually involves unpluging anywhere from 2 to 5+ cables. While that might not sound like much, doing it twice a day, five days a week (say, bringing your MacBook to the office) adds up to a lot of plugging and unplugging.
The new Thunderbolt display solves this problem with one cable the comes off the back, then splits into two, terminating in a Magsafe port (to power your MacBook) and a Thunderbolt cable (for everything else). That's it! You can literally undock this puppy in 2 seconds. However, if you have mounted hard drives, you should properly unmount them in the Finder before unplugging the master Thunderbolt connection to avoid the possibility of data corruption.
The only thing that I can find to complain about with the Thunderbolt display is the Y-cable that goes to Magsafe and Thunderbolt, the problem is that the cables should be a tad longer after the split. On the MacBook Air, the MagSafe port is on the left and the Thunderbolt on the right making it a bit of a stretch with the monitor cable. Granted, I'm splitting hairs, but another couple inches of cable would make it connect that much better.
All-in-all the new Thunderbolt Display is the monitor to get if you have a Thunderbolt-equipped Mac. It's a thing of beauty and it makes all other monitors hard to look at.