Just sitting here at work when I noticed the X suddenly pop up on the M screen. I thought "Uh oh!" but waited and watched it boot up normally. It was just sitting there, no LED blinking, not touched at all and last time I used it was a half hour before that to check the outside temp.
So, I let it finish booting up, then went into ALogCat to see if the logs it displays showed any error but nothing in the log was indicative of a fatal error causing a reboot. Just normal stuff as far as I can tell.
Is there then any way to tell why the phone just rebooted on its own? Could this have been a forced reboot by one of the apps that is set to automatically update? If so, shouldn't that show up in a log?