It depends on the brand what the defaults are, and it depends on the reversing switch for what it is in this particular model memory.
For Spektrum and JR, the default throttle pulse is narrow with the stick at the bottom. Most ESCs are programmed this way. Futaba, otoh, has a wide pulse at the bottom. For them to use most ESCs, they need to reverse the throttle servo direction.
The Spektrum and JR default movements are the same for compatibility with one another. Right Aileron = short pulse, Up Elevator = short pulse, Right Rudder = short pulse.
Next item: Servos go both ways too...
Andy
Same as here:
http://www.rcgroups.com/forums/showthread.php?t=2512068