Why can't I update my Nexus 4 to Lollipop? As I understand it, Android Lollipop (5.0) is now generally available over-the-air. My Nexus 4 briefly offered for an hour or two to install it. I said yes, and watched it start to download. When I next went to unlock my phone, it obviously wasn't installed. Now, when I go into the Settings app, and manually check for updates, it says my phone is up-to-date. It's still on Android 4.4.4.

I don't particularly want to install the developer image, as that'll wipe all the data from my phone. Is there any way I can encourage it to update?

I'm in the UK, if it's relevant.
It is possible to sideload the OTA update on a non-rooted, non-unlocked phone without losing your data (although it would be advisable to back up anything important that can't be restored from the cloud). The instructions here worked for me. This approach is not advised if you are not comfortable with working at the command line, dealing with windows drivers, etc. If you do do this, be aware that it takes up to an hour to complete, and for many minutes at a time there is no screen activity!

Alternatively, you could wait; IIRC (and I can't provide a source for this) the staged rollout was to continue until the end of November. Perhaps for some reason you have been moved further back in the list?