Good suggestions. I am in favor of a guest worker program, but I think there have got to be demands made on the workers and Mexico, too. So far, the details aren't very clear, and I think this is the time to make suggestions. It hasn't even been formally proposed or gone to Congress yet, so this is the time to do get in there.
Why? Read post 51. FBD has it right, in rather blunt terms.
There is no "labor shortage". We have 5-6% unemployment, which is most likely higher. We have people on welfare.
There's only one reason people hire illegals. To break the rules and profit from it.
That's it. Nothing else.