EFI32 Downsides?

[goMac]

Nothing to do with the language itself, but the 32bit API calls to the GUI would would only work for the Carbon interface. 64 bit applications have to be implemented via Cocoa to use the GUI (as a result of Apple's decisions, such as dumping 64 bit Carbon).

Correct. Just keep in mind this was mostly a political decision because Apple didn't want to carry Carbon forward. I was actually at WWDC when 64 bit Carbon was still around, it worked pretty decent. 64 bit Carbon was only removed later when Apple decided Cocoa would be the one true way. It was something that needed to be done, though.

This decision was also something made before K64 existed.

 

[NoNameBrand]

The only thing I've ever heard is that Apple has considered dropping 32 bit processor support, but not K32, as there are just way too many 64 bit machines that use K32.

I think that will happen first, as there's only a few models that used Core Solo and Core Duo CPUs.

Dropping support for K32 machines wouldn't be because of inherent support costs of K32, but rather simply testing against those old Macs; like Firewire, it's just a useful demarcation. Mind you, putting this on the system requirements seems a bit complex, they may just say "2008 and newer" (or whatever) for some release.