We did find (quite by accident) that Apple may have more reasons behind not installing Flash by default other than the stated reason of ensuring that users always have the most up-to-date version. Having Flash installed can cut battery runtime considerably—as much as 20 percent in our testing. With a handful of websites loaded in Safari, Flash-based ads kept the CPU running far more than seemed necessary, and the best time I recorded with Flash installed was just 4 hours. After deleting Flash, however, the MacBook Air ran for 6:02—with the exact same set of websites reloaded in Safari, and with static ads replacing the CPU-sucking Flash versions.

From page three of Ars Technica’s MacBook Air review. Battery life is one thing, but think of it this way: this means, potentially, that the majority of computers out there are using 20% more power than they should be. That’s a lot of computers using a lot of power. That’s pretty depressing from a conservation, reduce-reuse-recycle mindset.

I’m starting to seriously consider disabling my Flash plugin. And I’m a Flash developer by trade.