Went ahead and downloaded the newest, freshest version of iOS for that new iPhone 6? Then immediately regret doing so? Apple's released a statement saying that users who have lost carrier service or Touch ID functionality should reinstall the initial version of iOS 8, until version 8.0.2 is ready to go. The company says this will take a few more days. We've got the full statement after the break.
Update (9/25): That was quick! The new update is already out, find out more information here.