RangerMike, your diesel ran because of the carbon build-up in the cylinders which was preheated by the diesel fuel operation before the gas got there. You will find out soon enough (unfortunately) the damage that "dry" gasoline does to a diesel injection system. :(
So, will a diesel engine run on gas? "Kinda" I guess is the best reply- without the fuel switch over, the simple answer is no. Although I must say there is experimentation going on to make a gas engine that will ignite by compression... there sweems to be problems with emissions at this point- NOx in particular.