Immigration Suspension

Last night, President Trump announced that he will issue an Executive Order suspending all immigration into the US.
The President usually makes broad and sweeping pronouncements that are, in fact, very different from what actually goes into effect.
Exceptions, interpretations, and lawsuits can alter and sometimes stop whatever he is trying to do.
It could be a week or two before we have a clearer idea of who this will actually impact:

* Is it just halting the issuance of new visas at US embassies?
* Refusing entry of all non-immigrants (students, visitors, etc.) at US airports?
* What about returning green card holders?
* Will processing at USCIS for visa extensions be affected?
* Are there exceptions for health care workers or other essential workers?
* What is an essential worker?

The list goes on and on. We must be patient to see how this will ultimately turn out.