Updated models with AMD graphics options expected in early 2017.
Mac Pro Owners Still Waiting for NVIDIA 8800GT Option... Due Next Month?
A January statement by NVIDIA suggested a fix was imminent...
the company is "in the middle of bringing out an upgrade kit based on the NVIDIA GeForce 8800 GT solution for all Intel-based Mac Pros." What's more, this upgrade kit "should be out in a few weeks."
A recent email response from Steve Jobs suggests that the upgrade is still coming, possibly in the next month:
nVidia didn't come through, so we're having to do it. Should be ready in about a month.
Steve Jobs has been known to occasionally respond to emails, the most prominent example being an email in which he revealed calendar editing functionality that later came to the iPod touch.