NASA considered trying to regain control of the probe and retask it with a new mission, but money was short and NASA no longer had the equipment and software necessary to interface with the 30-year-old probe, nor the money to rebuild and reprogram as needed. So they dropped the idea.
Then, in April of this year, two men, Dennis Wingo and Keith Cowing, decided to see if ISEE-3 could be saved by dedicated civilians, using crowdsourcing for funds. With the assistance of NASA and the staff at the Arecibo radio telescope in Puerto Rico, and a lot of hard work by a lot of people, on May 29th they succeeded and took control of the newly rechristened International Comet Explorer (ICE).
They hope to be able to reprogram the probe to chase another comet. But equally interesting, to me at least, is that the probe will have a lunar flyby no more than about 30 miles above the moon. Who knows what it might observe?
I found out about this amazing achievement just today, from a "blag" written by Randall Munroe at http://blog.xkcd.com/2014/05/30/isee-3/#comments. He links to this report from the ISEE-3 Reboot Project with a lot more information (and links) about their progress: http://spacecollege.org/isee3/we-are-now-in-command-of-the-isee-3-spacecraft.html.
I hope I got all the details correct. If not, sue me. Or, better yet, follow the links I provided to see the details for yourself. Once again, enterprising individuals were able to do what government bureaucracy could not (and probably at a fraction of the money NASA would have needed to accomplish the same result.)