The  chart below represents new built home appreciation rates in Greater Phoenix for the last 20 years from 1988 to present.

Year	Median / New	% Change
1988	$ 103,950.00	----
1989	$ 105,850.00	1.83
1990	$ 109,300.00	3.26
1991	$ 107,500.00	-1.65
1992	$ 108,800.00	1.21
1993	$ 112,500.00	3.4
1994	$ 124,475.00	10.64
1995	$ 127,600.00	2.53
1996	$ 130,750.00	2.47
1997	$ 136,130.00	4.11
1998	$ 139,070.00	2.16
1999	$ 146,710.00	5.49
2000	$ 150,770.00	2.77
2001	$ 156,560.00	3.84
2002	$ 159,990.00	2.19
2003	$ 173,240.00	8.34
2004	$ 195,000.00	12.56
2005	$ 251,795.00	29.13
2006	$ 306,355.00	21.67
2007	$ 283,365.00	-7.5
2008	----	----

(Date from ASU Polytechnic)

Compare the above appreciation rates for new homes in Greater Phoenix to resale single family homes in Greater Phoenix. 

If you look at new homes in the real world you will see that in some ares prices dropped up to 50% from their high in 2005.  This is especially true if you take into account the incentives that builders are offering.

The real story is, that if you keep your home long enough it you will come out well, but if purchase a home during the recent highs, it may take a very long time before you regain your losses.