It really won't dissuade folks in that top 2% homeowners from buying, as the small amount of the mortgage deduction they get isn't a driver of sales at that top end of the market. So I expect the effect on builders and housing market to be rather tiny. But will have some effect, for sure.
And I don't know "that" much about the tax forms, but this deduction is phased out anyway based on your adjusted gross income. I doubt it will effect that many people in the end.