Google takes lot of time to throw OTA update to your phone, may be they do it lot by lot for not loading their servers, if you are lucky you got it early else wait for may days :p.
I was lucky i got it early but my nexus4 also had Ubuntu so at the time of reboot i lost that upgrade routine :(, and i was so eager to see brand new Android 5.0 Lollipop i Flashed my Nexus 4(worth it!).
Here are few steps i did for flashing my Nexus 4, that will upgrade your kitkat 4.4.4 (KTU84P) to Lollipop 5.0 (LRX21T), easy to do for you guys :)
First thing is to install ADB and Fastboot to your machine, i use ubuntu so apt-get is easy way to get it.
Now connect Nexus 4 to your machine via USB, make sure you enable your USB debugging ON, so start USB Debugging go to Settings » Developer Options » USB debugging. (If you dont have Developer Options go to Settings » About Phone » Build number and tap on Build number until you become developer).
Now try below commands to make sure you are connected to machine.
Now unlock bootloader
Turn off your Nexus 4.
Press and hold Volume Down and Power to enter the Fastboot menu.
Connect the Nexus 4 to your computer via USB cable.
Press the Volume Up button on the Nexus 4 to accept the command and press the Power button to confirm. The bootloader will now be unlocked, you will loss all data with this.
Download the factory image from Google, OR direct download clicking HERE.
Now the final step to Flash and install new lollipop image to your Nexus 4
This command will generate following logs on your terminal, put your password if prompted, your phone may be rebooted few times.
If your phone missbehave after finishing, just hard reboot it pressing power button for few seconds.