Erik Todd Dellums, the actor who voiced Three Dog, the disc jockey on Galaxy News Radio, tweeted to tell his fans that "there may be more of the Dog coming." He followed this up by adding "I was given permission to release that tease."
It's quite a tease, too, as a hint that a character may return obviously implies that the Fallout series will return in some form soon.
Update: Official comment from Bethesda is "no comment". The most intriguing kind.
This form could be anything from a sequel, to DLC to even just a flash game or free-to-play browser title. Whatever the case, it suggests that Bethesda are very much keeping the Fallout series alive.
We spoke to Bethesda's PR and they claimed to know nothing about this, either because they're also teasing us in their own, meaner way, or because they haven't yet been advised of what's coming next. Whatever the case, we'll let you know when we know.