I wouldn't worry about the engine oil, focus is better served on the transmission, diff and steering fluids. These should be changed out ASAP, then again in 5-10k to clean out most of the break-in wear contaminants.
After that's all said and done, you're just about ready to change the engine oil!
After this is finished, I would service everything based on using the Severe Service Schedule as the max change interval. All this is assuming you're concerned about keeping the car and keeping it in excellent operating condition.