will the cut of 4% acroos the board will boost demand?

Do you mean the cut of mortgage rates to 4.5% for home purchases (not refis) boost demand?

If so, yes. That and the $600Billion dollars being thrown into the credit market.

Our problem isn't the demand; the demand is there. The problem is that the money isn't there. Speculators pushed the market up, people who should not have recieved money to buy bought, and people (and businesses) eventually ran out of money to buy with because the banks didn't have money to lend (people quit repaying loans and the good loans when bad). That led to the crash of the market, people taking money out of the market, people losing jobs and cashing in retirement or turning the house back over to the bank, ad nauseum.

So, will the cut to a 4.5% rate AND money being freed up help boost demand for the roughly 4 million homes and 12 months of inventory on the market? Certainly. It should reduce 2-3 months of inventory and result in the purchase of some 500,000 homes. ...but it is only a temporary solution.