For those of you looking to alter the global MOV cap of 15, refer to these locations:
$08017D1E,$08017D26: Maximum MOV value a MOV-boosting item can take you to; default is 15
$0807FFA0: Maximum MOV; also defines how long to draw the MOV stat bar in the character screen. Higher values than 30 are possible, but don't look quite right.
This lets you double or triple the movement values for all classes and for all terrain movement data, which allows you to make movement values by class and terrain movement costs rather more granular. It's important that you scale movement costs with class move; a unit that can move ~20 squares causes serious pathfinding glitches.