I just confirmed this with the P-47D-25 in FS9. You are correct, the aircraft rolls away from the remaining drop tank instead of towards it which is obviously inaccurate.
You'll also notice that with the P-47D bubbletops (and I believe with other Thunderbolts in the pack) that the aeleron and elevator trim wheels behave opposite to their real-life counterparts
. Turn the aeleron trim knob to the right and the plane should roll to the right, but it rolls to the left in the sim instead. Turn the elevator trim wheel forward and the nose should tip forward, but it tips up instead in the sim. This may be related to the reversed weight loading of the drop tanks somehow. Maybe these two errors cancel each other out when the pilot is trimming for gradual fuel consumption out of the dual drop tanks; I'll test that next.
_________________I like Thunderbolts!
(Link to MySpace tribute page)120th Fighter Wing, Montana Air National Guard