And this is where I think they are missing a trick.
The pro can have a decent refresh. It could easily have new logic board architecture, a new set of ports at the front, a new range of graphics cards running in sli....
They have just left the machine to rot as they are no longer even a little interested in the professional market.
You woo the consumer market and persuade them to buy your phone, and these consumers then (in my experience) switch to using Apple laptops and/or desktops at home. These consumers are (probably) working (they can afford the apple tax, lolz), so if you offered them a decent corporate option, the chances are you would start to see an uptake in the corporate environment. Since they decommissioned the X-Serve, I have actually found the Mini to be a reasonable server for most uses (internal wikis, small to mid-scale project websites etc.) - the new Server App is very (almost too) straightforward, and the documentation is shockingly bad, but it is actually pretty powerful and far more approachable than Snow Leopard Server.
If I was at Apple I would be seriously looking at Enterprise-level cloud based server solutions for corporations, with integration between iOS devices and desktop machines and servers. It is the one area in which they have an untapped market. And there are certainly gains to be made, particularly with the Windows 8 mis-step that has meant several companies have started to at least consider looking at alternative software options.