@ lurkist
I assume you are asking will OS4 run on the classic machines?
The short answer is no.
The slightly more in-depth answer is:
OS4 is completley PPC based, so it will noe run on any of the 68k series of processors. That said, I belive that Hyperion are developing OS4 on A3(4)000's with CyberStorm PPC accelerators in, thus that will be the first version of OS4 to be released. Next will be the AmigaONE version and then the A1200 BlizzardPPC.
So, OS4 will run on 'Classic' machines, but only those with PPC processors
Hope that helps :-)