It appears that there is an issue with iOS 8.0.1 causing cellular service to be disabled. Many early installers are reporting "No Service" messages after updating. There are also reports of problems with Touch ID.
While all that sounds good, we’re also seeing reports of the update causing new problems – specifically, breaking Touch ID authentication and crippling basic cellular connectivity. Those sound like pretty serious glitches, so unless you’re explicitly having one of the problems this release is supposed to address, it might be wise to sit tight for a spell and wait for Apple to sort things out.
I'm not even surprised in the slightest. Honestly, most of the time It's better to wait a bit rather than jump straight into each new incremental iOS update (wasn't there also issues with iOS7 at first?). Plus, the more straining resources that reduce battery life and app loading times aren't worth the update for people with older models (like me).
tea
