The point of the Commission is to sign off on when the border has officially been 'secured' which would give the green light to embarking on the 'path to citizenship' for undocumented immigrants already in the country. Before that happened, those people would basically get a status that prevented them from being deported but it would be a highly contingent status.
Here's the text on the Commission from the Senate framework ...
We recognize that Americans living along the Southwest border are key to recognizing and understanding when the border is truly secure. Our legislation will create a commission comprised of governors, attorneys general, and community leaders living along the Southwest border to monitor the progress of securing our border and to make a recommendation regarding when the bill's security measures outlined in the legislation are completed.
There's been some question today about just what the Commission's role is. Is it advisory? Just there to say what it wants and basically a sop to border hawks? Or does it actually get to exercise some veto? The senators seem to say today that it's just advisory. But it sounds like this might be one of the fights we'll see on the GOP side, whether this 'Commission' actually gets to sign off and in effect has a veto on whether reform and a 'path to citizenship' actually takes place. Frankly, that seems ridiculous. The idea that you can ever truly 'seal' the border seems fanciful. But obviously you could tighten things dramatically. But that's a factual issue, not one the governors of individual states should be in a position to determine. After all, we're a nation. And this is a national issue, though obviously it has deeper effects on the states on the border.
Here's our report on the latest developments.