I was so hype and excited when I seen the release of the newly redesigned Mac Pro and held off on pulling the trigger on buying one because of the lack of Apple not having a new display to go with it. Then I read the rumors in the Buyers Guide only to see that Apple is actually adding support for third party monitors but yet till this very date no word of Apple coming out with a new display of their own. Does anyone here feel or think Apple gave up in looking to make a newer display from what they currently have? Personally if there were some beautifully designed "Glass" displays / monitors out there with a really high resolution for the Beautiful Mac Pro maybe I'd reconsider picking one up but personally I'd still prefer a nice Apple Display for an Apple computer rather than some third party monitor on the market.
Maybe Apple making a new Display is a pipe dream?
The answer to this is a little complicated. It's based around a standard not really present in any modern GPUs yet; DisplayPort 1.3.
The current 27" iMacs have 5k panels and drive it from a custom designed R9 280/380 chip.
The Mac Pro (Late 2013) has two custom 7870s and is capable of driving a 5k panel (potentially 3) but only with 2x MDP connections per screen. This is because of bandwidth limitations inherent to the current display standard DisplayPort 1.2.
Apple could easily create a 5k panel with its own timing controller, but having a monitor with two cables is distinctly un-Apple-like.
Now you might be wondering, then how can the iMac drive a 5k screen? Well, since it's an internal connection and an entirely custom part, Apple simply increased the width of the connection out of the GPU, sidestepping conventional connection bandwidth issues.
I believe when they release a new Mac Pro model next year, AMD and Nvidia should have reference designs for new GPUs that have proper DisplayPort 1.3 outputs that can drive a 5k panel with a single connection.
I believe that's what Apple is waiting for.