My school will upgrade the Macs to OS 10 when I tell it to, and I can't see doing that until there are mainstream applications that run faster in it, I'm sort of suprized that Photoshop 6 didn't come that way. If you do make a OS 10 version you are going to have to have a "classic" version in the install too, I hope you realize- just like installs that ask if you want the Powermac or 68000 version, otherwise you going to kill yourself in the Mac market. That would be the best solution for now, but currently I would guess (and it is only a guess, from asking around) less than half of the Mac owners have upgraded or will in the near future, do you want to cut yourself off from half your market?