Little article about the 2009 weatherization and PV tax credits here. Snips:

New incentives increase the size of tax credits for homeowners who buy qualifying products. For instance, those who invest in highly-rated insulation, replacement windows, duct seals, or high-efficiency heating and cooling systems can now receive a tax credit worth 30 percent of the upgrade cost (maximum credit value: $1,500).

"The federal government wants you to invest in solar and other renewables," Mr. Meier says. "Given all the tax credits, it may in fact make solar panels more cost-effective for the consumer than energy conservation," such as adding insulation or highly rated windows.