You can charge your Android device while having it turned off but Windows Phones, pretty much like iPhones, will boot up immediately when plugged in for a charge while being turned off. The HTC 8X, both the global and the AT&T carrier flavor, has started receiving its GDR3 update, and apparently the refresh solves this issue (feature?).
WPCentral reports that once the HTC 8X as the latest firmware, powering it off and plugging it in for a charge triggers a vibration, followed by the HTC logo, a battery icon, but no boot into the operating system. This could be useful for those who don’t want to be bothered by notifications (should they forget to mute or turn on airplane mode) as well as for maximizing charging power while minimizing charging times.