Gov. Arnold Schwarzenegger's choice of former Mayor Richard Riordan for state education secretary has education experts worried that despite his reputation as a pro-skills, pro-reform guy, Riordan's not all he's cracked up to be. These experts see Riordan as the power broker who spent far more time trying to fix school construction than classroom instruction -- the source of California's long education nightmare. Indeed, among a throng of educators who see California's new, intensive skills-based instruction producing miracles in grade schools, where achievement is up significantly after a generation of downward spiraling, Riordan might be stunned to hear that he is Worry No. 1.