Owing to the fact that I have excessive time on my hands, I have devised a game for us to play. It involves stating what date you think we'll get our first in depth information on the next Bone game. Telltale employees are not only allowed to enter but enthusiastically invited to. Hell, do it for Sam & Max and whatever unannounced project Telltale have going as well if you like. The person who gets the closest date wins the right to post and/or follow a link to said info.
My guess for Bone 3 is June 14. I base this on the fact that as far as I remember, the first indepth information on the Great Cow Race came in an Adventure Gamers interview on November 17, roughly two months after the release of Out From Boneville.
Like I said, I have far too much time on my hands, and the fact that I'm posting this sober, at home on a Friday night (which I assure you is not a regular occurrence) makes me feel as ashamed as you undoubtedly think I should.