Although Sony didn't revealed Xperia Z4 at the CES so far, but here is a good news from Sony CEO Michael Fasulo. He suggested that Sony will start the rolling out Android Lollipop from next month which means February 2015. He didn’t reveal the precise rolling out date. Xperia Z3 will be the first device to receive this update.
Earlier in October 2014 Sony executives mentioned that their entire Xperia Z series will be getting Android Lollipop. This means Xperia Z will also be among those devices which will be getting update. Sony announced Xperia Z two years ago at CES and main luring feature of device was ability to sustain the dipping without any harm.
Now as far as Xperia Z4 launch is concern, it seems Sony will be announcing it MWC 2015. By then, Xperia Z3 users will be having enjoying the latest build of Android Lollipop on their devices.