I think my move to Windows may be inevitable at this point just from a price perspective.
Adding 3 PCI slots via Thunderbolt 1, like the Magma ExpressBox 3t, is about $1000, as you can see here: http://www.magma.com/expressbox-3t.
And then let’s talk hard drives. So a 4 drive housing to replace the 4 internal drives in a MacPro. Promise has it’s 4 drive that also includes Raid 0, 1 or 5 so you don’t need to use one of your PCI slots, but new egg sells one with 4 1 TB drives for 1069, or 4 2 TB for $1699! And they will still be external drives, so you couldn’t put boot camp on them!
We are getting expensive here! Especially when a huge PC ATX case is less than $500. And you could get a MacBook AIR to keep a Mac in your life from $999 to $1700, which is less than these parts for your new MacPro!
Unless this thing is really inexpensive, or Apple comes out with their own expansion chassis I am nt feeling sold!