The Dell Latitude business laptops now have a wired led and wired switch. Besides the white led, there’s no indication which is on or off, and I don’t trust any of the software or firmware chain to be reliable. (score one for macs being transparent and prescient)
Dell should go back to the basic design of the Latitude E6400, but with modern electronics and screen of course, and drop the optical drive. The keyboard on that laptop was fantastic, and the single captive screw on the back panel was great for serviceability.
For some inexplicable reason Dell has chosen to mark the button as "mute mic" (mic icon + X). So if the LED on the keyboard is lit up, the microphone is off, or rather, the microphone muting is on on. Brilliant design.