"Pearl" for the week of December 8, 2008
Decline in sexual partners in Zambia
In addition to Swaziland, are there other recent examples of countries with generalized HIV epidemics where number of sexual partners has declined?

Yes, Zambia. The most recent (2008) UNAIDS Report on the global AIDS epidemic provides levels from the Zambia 2007 DHS which shows continuation of decline in proportions of men and women reporting more than 1 partner in the last 12 months:
As with Swaziland, there is concern about underreporting of numbers of partners, especially from women, but the consistent decline over 3 surveys with similar methodology provides some confidence some considerable decline is real.
Reference: UNAIDS. 08 Report on the global AIDS epidemic.
The "Pearls" offer answers to commonly asked questions about family planning. These "Pearls" are prepared by Dr. James D. Shelton, Senior Medical Scientist, Office of Population, United States Agency for International Development (USAID)