I have just had a quick look at the V4 tongue, and at first sight it looks a total mess. Many of the tongue actors are rotated in the default memorizes state, and I can't see any logic at all behind the rigging, it's just looks like a shambles. Perhaps there is some logic behind it all, but if so, the logic is beyond my comprehension.

[edit]Edit: huh, just checked and it's not curled up in zero pose after all, I wonder if that changed since the earlier releases of V4.  I hadn't bothered with the stock tongue in quite a long time.[/edit]

With all the rotations of the tongue zeroed, the tongue does point upwards at an angle of around 45 degrees. Perhaps the impression of curl up is because the actors are rotated in the default pose.

Many of the dials in the tongue are hidden by default. Attached above is the text of a pose file to show all the transform dials in the V4 tongue.