No Photostream, no upgrade..for me
Many people I have spoekn with said they won't upgrade because they took away photostream in iOS8. Until they put that back I am not going to upgrade. I am still shocked (and offended) that they would take away a feature that was roundly hailed as positive and IMHO the best use of "the cloud". It was great having a curated set of pictures on all devices (I own an iPhone/iPad/Mac/apple TV) while being able to store less curated photo files directly on the devices. This instance where the iOS got worse by taking away a feature is preventing me from upgrading.