Rents may not go down, but the dollar will be worth a lot less, so in real terms, rents will go down.
Also, now that financial firms will be declaring losses and therefore not pay taxes for several years, government services like the police might have to scale back. And unemployment is on the rise. Eventually Starbucks might move out of some neighborhoods.
All of this stuff happens slowly. After the stock market crash of 1929 everything was literally business-as-usual for most of the country for a couple more years.