Apple has released iOS 8.0.2. It's available now via Settings > General > Update or over Lightning to USB tether to iTunes on your Mac or PC. This comes just one day after the iOS 8.0.1 update left iPhone 6 and iPhone 6 Plus customers unable to use Touch ID or connect to cellular networks. Apple promised a fix within days and delivered it with a day. Apple also once agains apologized for the bugs:
iOS 8.0.2 is now available for users. it fixes an issue that affected iPhone 6 and iPhone 6 Plus users who downloaded iOS 8.0.1 and includes improvements and bug fixes originally in iOS 8.0.1. We apologize for inconveniencing the iPhone 6 and iPhone 6 Plus users who were impacted by the bug in iOS 8.0.1.
I've completed the update on my personal iPhone 6 Plus and both Touch ID and cellular data are working fine. We'll test the rest of the fix list shortly and let you know if anything comes up.
If you still have 8.0.1 waiting to install and you're not seeing 8.0.2, go to Settings > General > Usage > Manage Storage and delete it. If you get a verification error, update via iTunes instead.
Otherwise, if you install it, let me know what it fixes for you, and if any issues pop up.