I've just had a direct response from an nVidia representative after asking them a direct question on the matter. Here is there response:
Thank you for your submission. I wish I have good news to offer but Autodesk has decided to stop supporting external drivers starting with AutoCAD 2012. That is the main reason NVIDIA no longer offer performance drivers after AutoCAD 2011. This is not limited to NVIDIA GPUs and as far as I know this is true for AMD FirePro GPUs as well. Unfortunately there is nothing within the core of AutoCAD 2012 that will be able to take advantage of the Quadro GPU more than any other GPU without the performance drivers. The performance advantage that the Quadro GPU provided with previous versions of AutoCAD using the NVIDIA performance drivers is entirely gone.
Having said that we are working with Autodesk to better take advantage of the Quadro GPU in future release of AutoCAD, but I don't have any ETA on when this will be available. This is entirely up to Autodesk. This is a common question/concern, but unfortunately our hands are tied in this matter. We're doing all we can to assist Autodesk to take advantage of the Quadro GPU. We've published an article to our support knowledge base on this matter here: http://nvidia.custhelp.com/app/answe...AutoCAD%202012. I will make a post to the forum so others are aware of this limitation. Let me know if you have any further questions.
Very disappointing but I've asked in 2011 acceleration can be used instead. Here's my other thread over on the nVidia support forum: