Yes, a cloud storage solution for photos between Apple devices is long overdue. A system that will let me seamlessly store (not stream) iPhoto libraries from my Mac and the photos from my iOS devices. I should be able to access all of these images through iCloud.com and easily view, edit and share these photos.
The iPhone is the world's most popular camera, but you got to admit that managing and storing these photos are kind of a drag. More often than not, people just end up losing these valuable memories because they are unaware how to back them up, or have device failures. The cloud is the solution here.
Apple (Steve) said back in 2011 that the cloud would be the digital hub of the future, and we've achieved that for some things, like docs via Numbers, Pages, etc. and notes, contacts and calendars, as well as some apps, but not for photos yet.
I would absolutely pay Apple for this service. Yes, I am aware I could use Flickr, Google Photos or Dropbox to backup my photos but it isn't as seamless and I trust Apple more with my data.