Those of you who are affected by the iOS 8.0.1 update from earlier today still have the opportunity to downgrade back to iOS 8. Unfortunately, downgrading requires your iPhone to be connected to a computer, which might be an issue for many people, but this is still an option.
We recently published a post on how to downgrade from iOS 8 to iOS 7.1.2, and although firmware versions are different, we invite you to check out this post and use it as a base to downgrade from iOS 8.0.1 to iOS 8. In order to downgrade, you will first have to download iOS 8 from our download page.
Note that Apple will most definitely fix the iOS 8.0.1 issue that seems to plague only iPhone 6 and iPhone 6 Plus models. Because downgrading is a process that can take between 15 and 30 minutes, you could also wait for Apple to release yet another update (one that actually fixes things instead of breaking them).