I agree with most of you guys about the 32bit and 64bit cards. The previous gen mac pros can do the 64-bit processing so I dont see a reason why apple couldnt make a 32bit 8800gt card or update the firmware for the mac pro to support 64-bit efi 8800gt cards.
But in a business sense I think for apple and its share holders would benefit from this move since each newer released mac pros are tied down to a couple/newer specific cards. Because by doing this it puts the mac pro in line with the rest of the products (imac,macbooks,macbook pros).
By in line I mean it makes the consumer/businesses to upgrade the entire mac pro because of the influence of the cards. This is true even with the iMac and MacBook pros. If the mbp had the ability to upgrade the GPU every year Im sure half the market will just by the cheaper solution and buy the new GPU instead of the whole new mbp.
Basically CPU upgrade is not too crucial yearly but GPU is.
I have no doubt in my mind that this entire upgrade issue is business driven. They want people to buy these new Mac Pros that are not significantly different from the old Mac Pros.
This is a bad decision with regards to the Mac Pro. Everything in the Mac Pro could have been offered as an upgrade kit. From the motherboard to the new processors. The EFi should have been a free upgrade patch. Most people would have simply bought the new model with the upgrades built in but Apple would have created alot of consumer good will. Instead, Mac is effectively trying to sell a product to a very specific market that is not much different than the product the market already owns by effectively crippling the older product rather than introducing a product that is better on its own. Its basically cannibalizing its own customer base to squeeze out a few more bucks.
From a PC users perspective, this is so ludicrous that its hard to believe that a company would even think of doing this. It should have such an alienating effect on its customer base that it would be the equivalent of product suicide. I dont know how else to put this... but Apple thinks Mac Pro users are stupid.