Nope, no one has...at least on the forums. It might actually need a firmware update to enable it once W10 releases. Who knows whether the LED will actually work
it may or may not have the hardware, but don't assume it will get the feature until it happens.
Random story is that the Palm Tungsten T3 (2003), like many others, had a green LED light. But what was discovered was that it had a red one too that just wasn't used. Nothing came of it officially. (yes I know about VFS.LED, but that's third-party, with access we don't have here)