Right now Thunderbolt Display is special since it's the only monitor with Thunderbolt docking available.
Other needs to catch up, especially Dell as its closest contender. I don't know about you, but once Dell make a jump to Thunderbolt connectivity (it's available in a handful of PC now, so it shouldn't take long before other follows), I'd jump the wagon too.
I would go with
U3011, it's bigger, better, a wide @ss 16:10 with 2560x1600 for true workstation and once it has Thunderbolt, Apple should cry BIG TIME.
I believe it would have plethora of connectivity, so I can connect MBA and my future gaming tower, and then some .. and have tons of USB 3.0 hub and a "magic switch" to turn the display on/off normally, as in human normal. You hear that, Apple?
Oh, and it comes with 3 years warranty for free.
Just FYI, you can get a refurb TBD from Apple for $850.
True .. Except you don't need to scout refurb store to get a $700 Dell monitor. It's brand new in box, not a white plain box.
Oh, and like I said, you get 3 years warranty for free on Dell. Don't need to tie it up with AppleCare.