Apple has released a workaround for iPhone 6 and iPhone 6 Plus units that may have lost cellular connectivity or Touch ID support.
“We have a workaround for iPhone 6 and iPhone 6 Plus users who lost cellular service and Touch ID functionality today after updating to iOS 8.0.1. Affected users can reinstall iOS 8 through iTunes, for more information visit http://support.apple.com/kb/HT6487. We apologize for the great inconvenience experienced by users, and are working around the clock to prepare iOS 8.0.2 with a fix for the issue, and will release it as soon as it is ready in the next few days.”