I tried to use iCloud Photo Library and it wouldn't sync my whole library. It put up only about 100 of the 500 total and it was "completely" synced.
I went to Manage Storage in iCloud settings and deleted iCloud PL and it says it will be deleted in 30 days. It shows that the space was recovered immediately, though.
I think we need another CloudKit wipe because iCloud Photo Library is still out of control. It seems like it wouldn't sync right for me because I deleted it once before and waited the 30 days. It only uploaded pictures I took after disabling it that time.
This thing's going to be in the hands of millions in less than a month, too.
EDIT: Even after deleting, I still have 700mb of space being taken up by nothing. iCloud Photo Library says it takes up 0kb. I think it's incorrect. Beta 4 would delete everything from iCloud Photo Library. I may go to beta 4 temporarily to recover the space.