What could be one effect of the new bill? Well, apparently, it may contribute to shifting economic growth from the city to the suburbs: http://www.marginalrevolution.com/marginalrevolution/2007/05/should_immigrat.html
I have no idea how badly businesses inside cities depend on family labor, nor do I know the full social benefits of having a good family (though I support family life almost as much as I support free markets). However, it is important to note the opportunity cost in general; having more high-skilled immigrants means attacking the social capital that often enables small, family-owned immigrant businesses (and immigrants are the most likely group of people to be entrepreneurs!) to survive and prosper.