Download Oemden's Yosemite Beta and created a Sffot install on a 16 gig USB. Every time I try to boot from the USB on my Mac pro 1.1 it freezes on the black apple boot screen with text at the top which seems to imply a kernal panic. I must confess I am not terribly technically proficient however I am 100% sure I followed the correct steps in creating the USB key as I have already done so for Mt Lion and Mavericks.