It appears that AFCI protection will be required in almost all rooms in a SFD under the 2008 NEC.
California did not adopt the 2008 NEC yet, but it will be adopted in the next code adoption cycle, i.e. 2010 California Electrical Code, effective around January, 2011.
2008 NEC Art. 210.12 - ARC-FAULT CIRCUIT-INTERRUPTER PROTECTION (AFCI)
AFCI-protection requirements for 15A and 20A, 120V dwelling unit circuits were expanded again.
(B) Dwelling Units. All 15A or 20A, 120V branch circuits that supply outlets in dwelling unit family rooms, dining rooms, living rooms, parlors, libraries, dens, bedrooms, sunrooms, recreation rooms, closets, hallways or similar areas shall be protected by a listed AFCI device of the combination type.