Mailing the story:

Nagios sent me a reminder yesterday, which I finally got around to reading today, to update to the latest version of Nagios Core, 3.2.2. We were running 3.2.0, so we were a couple versions behind, so after browsing through the list of fixed bugs I thought it would be good to go ahead and upgrade. I had a meeting in fifteen minutes, and Nagios was actively monitoring servers in production. I considered for a moment waiting till after the meeting. After all, what if something went wrong during the upgrade, what if there was some unforeseen problem that caused disastrous results and caused me to miss the meeting? And then I remembered, this is Nagios. I did the upgrade, and made the meeting in time to get a cup of coffee on the way. This is how upgrades should work for everything.