The update will also bring back the Camera Roll, which had been removed with the release of iOS 8. At the same time, the iCloud Photo Library will be available so that you can save all of your pictures and video to the cloud. The feature ties in to your iCloud account and uses your available iCloud storage space. A smaller version of the pictures are stored on your iOS device, in order to use up less memory.
Another new feature, Instant Hotspot, requires a Mac with OS X Yosemite, to turn on the hotspot feature of an in-range iPhone running iOS 8.1. With SMS relay, iPads and Macs can receive SMS messages routed through an iPhone. While the Mac and Apple's tablets can receive iMessages, SMS messages have been limited to Apple's smartphones.
Among the bug fixes that iOS 8.1 will fix, is one that makes it difficult for an iPhone to pair with a Bluetooth device. While the update is expected to be disseminated on Monday, Apple has not yet released a time when we will start seeing notifications pop up on iOS devices.
source: MacRumors via RedmondPie