as discussed in the article, engines do run more efficiently (and emit less pollutants) when they are warmed to proper operating temperature. . .however, when your engine is cold, the computer gives it more gas and less oxygen (it used to be called "choking" the engine, before computers came along and did the job for you) and, on a very cold day, if you start up the engine and let it idle, where it's not under operating stress (pushing the car around), a lot of the fuel ends up not getting burned. . .and some of the unspent fuel ends up in your crankcase. . .and dilutes your oil, which increases engine wear.
i don't let my car idle. . .i fire it up and i drive. . .the engine temperature comes up much quicker when the engine is actually working, and it's better for the overall life of your engine. . .my $.02.
I'm not talking about 10 plus minutes. I am talking at least 30-60 seconds on a cold start due to the lubricants being settled and thicker.