Since I reached the limit of my patience with Apple's Customer Service, I have huffed and puffed ( a LOT) down the phone.
The case has been promoted once more up the Apple food chain and further signs of movement on the issue are apparent.
Nothing yet definitive however.
I begin to hear from Apple that since this is a new product (albeit eight months since introduction), there is no precedent for actually replacing a machine at this level - thus their rather delayed and hesitant responses. If this is correct, it speaks well of the product's reliability if not of their customer service.
I guess you can always be the first at something - dubious privilege as this instance is.
I will update further...
I feel for ya Chris, but you know a macpro is way down the food chain when it comes to apple's bottom line. You go into an apple store and they have three stuffed in the back, though you pass by 45 macairs, 22 imacs and 1250 phones before you'll see one.
Use to the macpro was the king of the Apple Jungle and since they made most their cash of us graphic pros, they listened, now we're about 4% of their bottom line, if that.
Through I know you like FCP X, when they came out with that beast it was clear their market stopped being the working image maker and moved to the amateur blogger/filmaker/silver lake resident.
I know today I'll buy an Imac cause they don't break the bank, I can buy two for one macpros and even then if I wasn't so deeply vested in Apple stuff, which seems to be all hooked together, I'd switch to custom made PCs in a blink.
Not that you need my opinion but, if I ended up with a dead machine and a response like you've been getting, I would have a law professional write a letter asking for full refund and a do over.
There is just no reason to lose this much time, but once again, I truly wish you well.