I am sure there will be a next Mac Pro. And Macbook Pro. And Mac Mini. And MB Air... or a similar replacement with a new name. The whole Mac line is old, and software is half baked (Metal, old openCL/ -GL). Pro app rumors suggest that something big is coming. I hope this WWDC will open up the mystery.
I expect a big change to OS X and how it's used and that it brings a new approach for hardware - hence no upgrades.
Recents Apple patents: Movable Illuminated MacBook Trackpad, login to Mac with iDevices' TouchID, Hover-Sensing Multi-Touch 3D pointing Display, Three Dimensional User Interface Session Control using Depth Sensors, Pressure-sensitive switch-less QWERTY input mechanism keyboard, reconfigurable MacBook with configurable, force-sensitive input structures, keyboard with Multiple Colored LEDs, Liquidmetal's alloys, eye-tracking technology used to control a user interface, Stylus/pointing device with motion-sensing hardware, including accelerometers, Inductive Charging Between iOS Devices, Watch & MacBook, Automatic Shutter System that will protect iDevice and Mac Ports from Moisture or Dirt, protocol to support parallel processing with low latency, Virtual reality stuff*, a Stereo System with an Adaptive Room Equalization Feature...
*(Apple has filed a multiple patents for VR & AR, even for OS X user interface, has bought companies making software products for VR & AR. Finacial Times reported, that Apple has a large team that is experimenting with headsets and other technologies. Apple hired Doug Bowman, one of the U.S.' leading virtual reality experts. Tim Cook said that he does not believe that virtual reality is a niche. "It's really cool," he said. "And it has some interesting applications.")
My point here is that Apple still invests on Mac innovations and something new is coming up.
Recent FCP X preview (under NDA) could point to an audio overhaul, with things like roles based mixing. Don't see Apple abandoning FCP X anytime soon .
Would it be finally an OS wide support for DSP. All recent Radeon GPU's come with a DSP and Apple has also its own what they've been using in their ARM SOC's.