Lloyd Chambers, who is a photographer, did a comparison between his 8 core 2013 Mac Pro and a 5k iMac and the iMac held it's own for all but the most demanding operations for Lightroom and Photoshop. I have seen many posts from people who chose an iMac over a Mac Pro for graphic arts and a couple from people who actually use one for video. That being the case, I could see Apple trying to make the iMac a bit more powerful and letting the Mac Pro become history.
It would simplify the Mac lineup to a MacBook, MacBook Pro and iMac which are probably much stronger sellers than the Mac Pro and cater more to the average consumer. I think the writing is basically on the wall when they showed a MacBook Pro hooked up to multiple monitors and hard drive enclosures.
What just saddens me is that Apple could still make a Mac Pro, with ridiculous specs.. and I'm sure they would sell more than their fair share (if they didn't go full lunatic on the pricing....) even if only to be used as a halo device. It's not like they don't have the money or the resources. And it's not like their most loyal customers don't deserve it. Instead they just seem determined to cut everything to the bone, whilst taking a hot dump on people who've been buying their hardware for years and built them up financially to the point of being able to go down this obsession with iDevices.
Thankfully I'm not too invested in the Apple ecosystem.. so whilst my disappointment is huge about what Apple are doing, purely from the perspective of someone who is a tech enthusiast, it doesn't affect me too badly. My only direct Apple tie in was that I'd started to use their Photo's app to import and manage my pictures, and now I need to go through the pain of getting them all out of there and into an equivilant Windows app. Shame.