It really depends on whether your counting number of chips or dollars in sales. POWER chips sell at a premium inside high end enterprise systems, while MIPS is embedded in lots of places like handheld consoles and routers for more chips sold but for less money.
The high end POWER chips from IBM makes up a miniscule fraction of the overall Power/PPC market in terms of units. PPC sells in comparable unit numbers to MIPS, but mostly from architecture licensees like Freescale.
