Why Do We Still Use Clock Frequencies?

Mr. Sketch asks: "With all the multiple pipelines, prefetching, caching, etc., that goes on in modern the (Bogo?)MIPS be a more accurate measure of a processors speed? If this is the case why don't chip manufacturers rate and advertise their chips with the MIPS value speed, but it seems like nowadays the MHz value is pretty much meaningless and we (as well as chip manufacturers) need to be using something else to get an accurate measure of the speed of a processor." I agree that clock frequency is next to meaningless when it comes to discussing the real speed of today's processors, but would MIPS really be a better replacement?