Even if there was a 4K Thunderbolt Display, you can't connect it to any Mac as 4K requires Thunderbolt 2.
I would expect the entire Mac lineup to be updated to Thunderbolt 2 once it and new models are released.
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And also hints that we won't get a new TBD until Thunderbolt 2 is officially released. There's no reason to release a new TBD only to see the Thunderbolt feature passed by just a couple of months later, so expect it to be delayed until Thunderbolt 2 is released.
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i know this will sound weird but did you notice when Phil Schiller introduced the new Mac Pro he said something like "and of course you want to use them with third party monitors, it support 3 4K Displays"
it's like yeah....we will not be making new Displays anymore...at least this is how i saw it.
after they stopped making docks for iPhones i wouldn't be surprised if Apple stopped making displays too as they are much expensive than other displays in the market and they don't represent much of their sales...
No. The new Thunderbolt Display will take Thunderbolt 2, which will do 4K, they're just waiting until Thunderbolt 2 is ready for release to bring out the updated Thunderbolt Display. Thunderbolt 2 is on target for a Fall release right now. (But since Intel is also working on it don't be shocked if it is delayed)
Also, when they say 'third party' while referencing the Mac Pro, understand that a huge demographic of the Mac Pro users are professionals who use all sorts of third party products to edit video and photographs, music, etc. Those third party peripherals range from external hard drives to external video cards to external docks to external displays. And how do you think those third party peripherals are going to hook up to the new Mac Pro? With Thunderbolt 2.
Apple didn't help create the Thunderbolt interface, and then double it's speeds (in version 2) only to stop using it. The new Mac Pro has 6 Thunderbolt 2 input/outputs, and each can daisy chain up to 6 other Thunderbolt 2 devices. That means a stock Mac Pro can use up to 36 Thunderbolt 2 devices. That doesn't sound like Apple is giving up on Thunderbolt 2 and the Thunderbolt Display. They've already leaked a desktop wallpaper at 4K resolution.
So don't get down, I just wouldn't expect a new Thunderbolt Display until Thunderbolt 2 is released, which again, looks like the Fall at the earliest. And I would expect all new Mac products/revisions starting around the Fall to include Thunderbolt 2.
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Would this mean, then, that no current MBP or MBA could drive the next ATD?
I don't think current MBP or MBA or mini's or iMacs/anything with Thunderbolt 1 will be able to drive a Thunderbolt 2 4K display. Maybe they will have some GPU upscaling chip built into the Thunderbolt 2 4K display since it already has a ton of chips inside, it's like it's own computer anyway. But I wouldn't cross my fingers on that.
Here's an interesting article on the tear down of a Thunderbolt Display by iFixit and the 13 different chips inside.
http://www.ifixit.com/Teardown/Apple+Thunderbolt+Display+Teardown/6525/1?singlePage