I didn't get everything I hoped for here, and neither did many Macworld readers. For starters, there's no traditional drive bay at all—just solid-state storage on a removable card—disappointing the many readers who wanted multiple bays. It appears you'll be able to upgrade that flash storage (whatever the stock capacity ends up being), but if you want to use traditional hard drives, you'll need to put them in external enclosures and connect them using either Thunderbolt or USB.
I actually expected this: As I wrote in March, "It's not hard to imagine Apple making a smaller Mac Pro and suggesting that those who need more storage instead take advantage of Thunderbolt." But I did think the new Mac Pro might include a both an SSD and a large-capacity internal hard drive, configured together as a Fusion Drive. Instead, Apple went all solid state inside, and I suspect many pro users will end up appreciating the better performance they'll get.
(And using external drives for additional storage isn't exactly horrible in terms of performance—7200rpm hard drives aren't fast enough to be limited by Thunderbolt, and USB 3 is more than capable enough for all the but most-demanding storage uses. But this approach does mean more cables and components on your desk, and it means that you'll need to buy external enclosures for extra drives.)
It appears the new Mac Pro will support up to 128GB of RAM, which is twice as much as the current top-of-the-line Mac Pro, making many high-end users very happy. The downside here is that the new model has only four memory slots, compared to eight for today's top-of-the-line model, so maxing out memory will require 32GB DIMMs, which will be very expensive.
One area where a good number of pro users will be disappointed—over the long term, at least—is video: It doesn't appear, based on what Apple's revealed so far, that the new Mac Pro's GPUs will be upgradeable or replaceable.
The consolation here is that it the stock GPUs will apparently be very fast, and, of course, you'll get two of them. Still, there appears to be an assumption that pro users will be ready to upgrade the entire machine by the time those GPUs are obsolete. But comments from our readers indicate otherwise: For example, there are many Mac Pro users who've been able to keep even 2008-era Mac Pros current by just swapping out the video card—the CPU itself remains fast enough for them. We've also heard from video pros who use software optimized for Nvidia GPUs: The new Mac Pro's use of AMD components means these folks will have to look elsewhere for their next computer—or at least wait to see if that software gets updated for the new Mac Pro.
Sign up for CIO Asia eNewsletters.