Rejoice! Google has started pushing the over-the-air updates to Android 5.0 Lollipop out to Nexus devices, so over the coming days you can expect an update notification on your phone or tablet. In case you don’t want to wait, you can grab the system images straight from Google and update manually.
I just updated my Nexus 5 to Lollipop manually, and everything went okay. It’s smooth, and the new Material Design is a breath of fresh air. Not much to report after an hour, of course, but it does feel like an entirely new phone.