Yes, Yosemite 10.10.3 and Photos are released to the public beta. Now the question you may ask is how do I get to the public beta for Yosemite and photos? Well if fairly easy really all you need to do is sign up for the OS X Beta Program. Once you have signed up click the “enroll your mac to receive beta updates.” Then your set just update your Mac to Yosemite 10.10.3 and download the Photo application. If you have a secondary mac put 10.10.3 on your Mac. I highly disagree to put 10.10.3 and photos on your Mac until it is officially released to the public.