Tbd when the current Mac Pro will become a collector's item; also see The Mac Pro Lives (Daring Fireball)
"Apple is finally talking about its plans to refresh its Mac Pro. In an interview with BuzzFeed News, Apple’s Phil Schiller claims the company is “completely rethinking the Mac Pro” after its last refresh back in 2013. While Apple is currently building a new Mac Pro, it won’t arrive this year. Schiller says Apple is hard at work on a new Mac Pro system with a separate pro display, but it's not clear exactly when either will arrive. The team responsible for both have been told to take their time on designing the next Mac Pro, to avoid some of the design constraints of the existing model.Apple working on ‘completely rethought' Mac Pro and pro display - The Verge
“We designed ourselves into a bit of a corner,” admits Apple’s Craig Federighi, who looks after software engineering and regularly appears on stage at Apple events to demonstrate OS improvements. “We wanted to do something bold and different. What we didn’t appreciate completely at the time was how we had so tailored that design to a specific vision that in the future we would find ourselves a bit boxed in — into a circular shape.”"