NDA.
But if one was so inclined, such things are in the Mac developer site for Mountain Lion.
Bull, that has nothing to do with the EFI 32 bit Bios, and to top it all off, THE only thing NOT 64 bit is the EFI BIOS.
This has NOTHING TO DO WITH the 64 bit code of the OS, The Mac Pro is a full 64 bit Machine.
Only the EFI Bios is 32 bit.
As with the first release of Lion, the Mac Pro 1.1 was not supported due to the base line testing of the System and drivers, Apple needed to get as much info back on System Performance and any crashes it could, so they stuck with the Newer systems to test, support was later added in beta refreshes,
And don't be surprised as testing continues and additions are made & fixes put forth, that the Mac Pro 1.1 & 2.1 are added to the list of systems supported computers.
I also believe if all those whom are concerned, Let Tim Cook be aware of your feelings, in today's economy, those Systems that had been sold as full 64 bit workstations should still have support.
And no one confuse a desktop system with the Mac Pro that is sold a Professional Workstation, Workstation's are at the Norm suppose to last at least up to 7 years, if not more. And at a $3,500.00 price in 2007 rightfully so.
The NDA, Really?
There is Nothing that states that, I have read through that whole site. And I'm not going any further then that other then to add, The information you posted was in itself deceiving.
Don't confuse the 32bit EFI BIOS with Drivers, they are different and you are confusing the situation.
A Mac Pro can run all 64 bit drivers in Mountain Lion, only the 32 bit boot EFI is stopping it, as with Lion, All Apple needs to do is add a 32bit code line for booting just like they did for Lion and it's done, they can also send out a 64 bit EFI bios update, but it would be hard to see this happen.
"What people want is real answers, some just push out crap to sound like they know everything under the sun, that in itself is a disservice to the Apple Community."