A guest worker program would be a benefit to the US economy, and would only be codifying and regulating events that are already occurring. There is no reason to keep workers out of the country based on race or country of origin, and having a large number of unskilled but low cost labor (or high skilled/high cost, possibly) would be great for industry.
I think having a guest worker program would be a good thing. This way their would be more incentive to register in the US to work. With so many illegal worker in the US ..There needs to be some way to discourage businesses from using this type of labor. Also a guest worker program could be a benefit for students from other countries who are here temporarily or visitors who may only be here for a few months as a way to learn and make some type of income while they are here.