1) Real Estate investors, home buyers, and companies looking to relocate employees would probably pay close attention to this report.
2) The statistic is actually split in to four different reports; a national home index, a 20 city composite index, a 10 city composite index, and twenty individual metro area indices. The homes that are taken into consideration are all relatively the same size and have already changed ownership - they want to see what people will pay for the same home overtime - it excludes new homes, condos, and drastically remodeled homes.
3) The index was set at 100 in 2000 and from then on it grew to 188 in 2006 - the housing bubble popped - and has been in a steady decrease since. The current measurement is 145.