According to a few articles, an amateur astronomer named Scott Tilley, while searching for ZUMA, spotted some errant radio signals coming from the location of the IMAGE satellite, which failed about ten years ago.
https://gizmodo.com/over-a-decade-later-nasas-long-dead-image-satellite-ma-1822479068
The best speculation I've seen suggests that IMAGE was briefly eclipsed by the Earth, draining its batteries, and once outside of Earth's shadow, went through a full system reboot, and cleared whatever error state had shut it down in 2005.
Also reported was that the telemetry suggests at least one of its six instruments is functional, and NASA is apparently digging through its archives trying to figure out if they can restore communication with IMAGE.
While the scientific return would probably not be huge, since IMAGE's primary mission had been a complete success, it could definitely be a neat story. And if they do bring it back online? Hey, free science satellite!