I can only tell you that I've been doing some light testing with some CS6 programs on a Win 8 Release Preview machine with no apparent problems.
Thanks Bob, this is encouraging to read.
Microsoft does seem to care about backward compatibility so I wouldn’t be too concerned about CS6.
I would think anything that runs on Win 7 should be fine on Win 8. That said, I wouldn’t push my luck with anything older than CS5 but it wouldn’t surprise me to see CS3 and later working okay.