Its a PPC. Although I am about to scrap this computer (thanks faulty Temp. Sensor), so it looks like I might be PDF quite a few other things as well.
For what it is worth, I have AC7 and AC8.1 running frequently on Mac Intel. I've never had one issue...
Just keep in mind to backup your present (PPC) AC installation folders to copy on any Mac Intel. The software is fine, CD installation application isn't.