Have the tax credits been extended for 2012 and 2013?

Have the tax credits been extended for 2012 and 2013? Are any products currently eligible for a tax credits for energy efficient home improvements?
Yes, tax credits have been extended for 2012 and 2013. 

The tax credits for the following products are effective through December 31, 2013:

• Windows and Doors 
• Insulation
• Roofs
• HVAC: Central Air Conditioners, Air Source Heat Pumps, Furnaces and Boilers
• Water Heaters: Gas, Oil, & Propane Water Heaters, Electric Heat Pump Water Heaters
• Biomass Stoves

Tax credits are still available for the following products (through 2016):

• Geothermal Heat Pumps
• Solar Panels
• Solar Water Heaters
• Small Wind Energy Systems
• Fuel Cells

• Can used or second hand products qualify for the tax credit?
• Can two people living in the same home both get the tax credit?
• Are there rebates for buying ENERGY STAR qualified home?