iOS 8.1: Text Message Forwarding

One new feature in iOS 8.1 is: Text Message Forwarding
Any text messages sent to a phone number on an iPhone will be forwarded to other iOS devices using the same Apple ID.

Go to: Settings > Messages
Enable Test Message Forwarding for other iOS devices. They have to be logged in to iCloud using the same Apple ID with the iPhone.

One thing I noticed is that at this point I cannot forward text messages to other (service-less) iPhones.

iOS 8.1: Text Message Forwarding

iOS 8: Wi-Fi Calls or iPhone Cellular Calls

iOS 8 brings two features that are mutually exclusive: Wi-Fi Calls and iPhone Cellular Calls.

Wi-Fi calling will be turned off to allow other devices to make and receive calls through your iPhone.

iPhone Cellular Calls or Wi-Fi Calling

Wi-Fi Calls is currently enabled on carriers that support the feature, such as T-Mobile USA.

T-Mobile Wi-Fi Calls e911 Address

iOS 8 also enables Cellular Calls handoff to OS X Yosemite and other iOS 8 devices.

Apple Seeds iOS 8.1 beta 2

Apple seeds iOS 8.1 beta 2 build 12B407 to developers on Tuesday, October 7, 2014; eight days after the first iOS 8.1 beta.

iOS 8.1 beta 2

Chatters within Apple suggest that iOS 8.1 is slated for release along with OS X Yosemite.