Telltale has put up their official page for the fifth and final episode of Sam & Max: Season 2, which is indeed titled What's New, Beezlebub? Check out the plot outline, which confirms what the ending of Chariots of the Dogs hinted, that Sam & Max will be visiting the bowels of Hell:
Judgment day is at hand, and it's time for a showdown with the guy downstairs to bargain for Bosco's soul. But in the corporate wasteland known as Hell, not even the Freelance Police are safe from eternal damnation. Can Sam & Max fight free from Satan's grasp, or have they reached the end of the line?The page includes all the usual good stuff, including a great trailer, and some screenshots and concept art. See it all!
(Spoiled it for me :'( )