Let's take your comment in two parts.Not really, Apple needs to spend money on designs and development to be competitive. That can mean new case designs, but it also means frequent upgrades. 6-8 month upgrades of the Pro machines would be far more appropriate than 17+ months. .. if Apple was serious about pro-users.
...
The first case design... The case design works. they have room inside to do updates as needed. A professional doesn't care if the outside of his new machine looks the same as the old machine. Heck in truth, that professional is relieved that he doesn't need to get new furniture to use a new computer.
And secondly update interval... I hate updates just so a company can say they did an update. Apple should do small silent updates that reflect disk capacity changes and pricing changes every 3 to 6 months as appropriate. Oh and if Intel releases a slightly faster processor, add that with the other minor changes. Apple can't release real changes faster than Intel gets them the new processors. And as someone that had to deal with hardware maintenance, I like the idea that I don't need to maintain more and more spares for constantly updated hardware. In some cases a spare is an identical system that you can pop the disks into and then get Apple to repair the broken system. (And then the repaired system becomes the spare. You can't do that if the machines vary too much due to office politics.)
Getting back to the rumor that started this thread... I could see Apple getting the processors for the Mac Pro about a month early from Intel. Remember an August announcement could mean September shipments for the Pro. And I can see Apple doing something to make the Pro rack friendly. So in this case some sort of case change could be in order.