Reports indicate that the Android 5.0 Lollipop update for Nexus devices brings a new option under the Voice settings option, called Hands-free. The feature, which lists voice search and spoken notifications, can't be turned on for now and is only expected in a future update for the Nexus devices and Lollipop as a whole.
The spoken notifications feature reads out the user's notifications upon asking the handset "What's up?" or "Read my notifications". Currently, the Moto X series of handsets with the Moto Assist feature are the only ones to perform this function.
(Also See: Android 5.0 Lollipop Review: A Sweet Upgrade)
The search giant has not commented yet about the inclusion of this ability in its Android 5.0 Lollipop update. Notably, the option is said to be visible only when the the primary language has been changed, and disappears when users return to the menu.
It is worth noting that the screenshot showing the 'Hand-free' option (via Gadgetzarena) yet has no toggle switch to activate or deactivate the feature in the current Android 5.0 Lollipop build, and is only expected to be rolled out with a future update.
As Gadgetzarena notes however, since the feature does not require digital signal processing (DSP) found in the newer Nexus devices, spoken notifications should probably roll out to other devices - with the Nexus lineup expected to be first.
Notably, Google updated its Search app for Android on Wednesday, bringing the Always On Voice Recognition feature to select Nexus devices and a few select Android devices like the Galaxy Note 4 with DSP, allowing users to activate the voice search feature with the 'Ok Google' voice command even when the device is asleep.
For those unaware, the Android 5.0 Lollipop OTA update has started rolling out to Nexus 5, Nexus 7 (2012 and 2013) Wi-Fi only models and Nexus 10 along with the Moto X (Gen 2), Moto G and other handsets.
Additionally, Google has also released factory images for the Nexus devices - Nexus 5, Nexus 7 (2012 and 2013) Wi-Fi only models and Nexus 10 - that are receiving the Android 5.0 Lollipop update. There are no factory images for the Nexus 4 and Nexus 7 (2012 and 2013) 3G/ LTE models yet. However, we can expect Google to start rolling out Android 5.0 Lollipop to Nexus 4 and Nexus 7 3G/LTE models soon.