Vague? I can't prove that the game is in development, and we don't know it will be anytime soon, but they have said on several occasions that they have every intention of continuing the series. They probably wouldn't put "Bone 3 - coming soon" on the front page if that weren't true. I can recall at least two interviews where Dan Connors said they would continue Bone after they were done Sam & Max (though not necessarily immediately). Emily has confirmed on this forum at some point that they're not abandoning the license.
Are they flat-out lying? Maybe!