The SNB released the latest SDDS data which also include FX reserves figures for September 2012:

FX reserves were CHF429.3bn in September, compared to 420.8bn in August, an increase of 8.5bn. It’s quite certain that Swiss reserve accumulation has slowed down considerably, although it’s not negligible (around €7bn in September). This lower growth should reduce the AAA securities premium introduced by large SNB purchases.