[rkagerer]

This would be a really useful thing to indicate via an unobtrusive LED on the chassis somewhere.

[echoangle]

Why would you take an LED over something on the screen? The notification is only really relevant while the laptop is open, and the screen is going to be on anyways.

[alexford1987]

There is no way Apple would do this on a MacBook Air, which is able to be passively cooled because of the type of use cases/users it is primarily designed for, most of whom never hit throttling. The light would only confuse almost everyone.