I've been thinking about a possible iMac Pro in 2013 to replace the current Mac Pro. What I'll write is about my workflow and obviously may not be "ok" for others. First of all, I don't need 4 internal hard drives anymore. Before, I was using the internals as a RAID0 to speed up things, but nowadays we have SSD, so we don't need a RAID0 to boost OS/app performance. Single disk is ok for most stuff. If someone is doing video capture and requires a 6 disk RAID0 with SSD's, he/she can do that externally with thunderbolt now. I don't need 3 PCI slots. I've been using one except the GPU for eSata I/O, but now I don't need it due to USB 3.0. There are obviously some specialty PCI hardware which cannot be replaced today, but I'm pretty sure that if Apple dumps PCI altogether, most manufacturers will come out with Thunderbolt versions. GPU is one of the few places we need the PCI bandwidth. Sound/video editing cards can work with TB and give a similar performance. I don't need an internal optical drive, I bought and external Blu Ray drive 2 years ago and still use that instead of the internal drive on my Mac Pro. These were the stuff I don't need from Mac Pro. Now the stuff I need from Mac Pro. Dual Processor. Now, I don't really know if Apple can actually fit two Xeon's into an iMac chassis. If they can't, this is a deal breaker for most. Desktop GPU. I'm pretty sure a big GPU can be fit into an 33" iMac chassis. There's more than enough room for that one. Ram: I think newer Xeon's can use Non-EEC memory, so SO DIMM's should work with those. In that case, one can easily fit 64GB Memory into a 33" iMac. In this case, the biggest issue seems to be fitting dual xeons into an iMac chassis. If that can be done, I'd love a new 33" iMac, possibly with a 2.5k vertical resolution. Put a 4500$ price on that and I'll buy.