after a lot of thought, i finally went ahead and purchased a Quadro 4000 for Mac from Amazon via overnight delivery yesterday. the Quadro arrived as scheduled today, and I installed it in my 2010 12-core Mac Pro running OSX 10.6.6, but it does not seem to work with the latest version of Autodesk Maya 2011. i installed the graphics card correctly, made sure the most current drivers were installed, and booted up my computer. the computer recognized the graphics card just fine. but when I launched Maya 2011, none of the viewports showed up and the OSX beach ball just kept spinning, and Maya was "not responding". i tried deleting Maya preferences, and even tried setting up a fresh new user account, but it was a no go. since i have Autodesk Gold Support, i called up Maya Tech Support, and they confirmed that they haven't tested the Quadro 4000 for Mac themselves yet. they also weren't surprised that it wasn't working. i already set up a return for the Quadro, and it'll be going back to Amazon at some point today. i'm quite frustrated cause my 5870 is causing some major viewport lag issues that are hindering my ability to create large and complex Maya scenes. i guess Autodesk is working to resolve this issue asap. if your curious about the Quadro 4000 with Maya 2011 under OSX 10.6.6, well, there you go, its not working.