What I am doing is using AirDrop to move my pictures over from my Mac to my iPad which then puts in into iCloud Photo. It will take me a long time to do this since I have 35GB of photos, but I figure I'm in no hurry. I do basically a folder at a time, AirDrop them over and then I give IOS Photos time to do it's thing. This is about the only way to do it until Photos for Mac comes out.