On the one hand, to my knowledge everything pencilneck listed in the original post is factually correct, and reason for concern house prices will keep falling.
On the other hand, the employment forecast for late 2010 into 2011 is pretty good. Job losses have mostly stabilized, and sooner or later job growth will start. The “green shoots” are growing a bit more. So the employment picture will get a little better.
I actually expect housing to be pretty flat for the next two years. No serious further collapse in price, but no sudden rebound either.
