Pharmacology is a huge part of the Pharm.D. I would say majoring in pharmacology would give you a huge advantage in your studies, and a varying advantage in the admissions process of different schools. It certainly won't hurt you.
Since I have one, I can tell you that with just the degree alone, you can be employed in the biotech or pharmaceutical industry as a research associate. Or you can take a position as a laboratory technician in a research laboratory. For the most part, thats what pharmacology majors end up doing - research related stuff. Some of us end up going into pharmaceutical production, but thats more for the chemistry majors.