First off, the Constitution is important. Even President Obama said he "welcomed" this discussion, though one wonders how seriously the President meant it. The smears against Snowden have already begun, and the DOJ has already launched a criminal probe targeting Snowden. Ultimately, I think this is a great discussion to have, and it is well-timed to minimize the damage that it might do to either Obama or the Democratic Party (after Obama's re-election, after his expected honeymoon period, and yet 17 months before the mid-term elections). I think Snowden and Greenwald timed this release very carefully and prudently. That said, the 4th Amendment matters to many, many Americans, and it's good to have this discussion.
Second, and more importantly, I don't think we have grasped, yet, the implications of the information Snowden released. So far, most of the discussion I have seen centers on whether the NSA's data-collection activities violate the rights of Americans. But what about the rights of the rest of the people in the world? What's most embarrassing, here, is that Snowden and Greenwald have just announced, to the entire world, that the U.S. has the capability (and assumes it has the right) to capture and record not only meta-data from phone calls but all digital information (from any source) that passes through internet servers in the United States. What's more, 4th Amendment protections do not apply to non-citizens, so the world now knows that we are recording all data that comes into the country (via phone or internet) and we reserve the right to look at any or all of it, for any reason, at any time, without any real oversight. Even if there is some kind of judicial or Congressional oversight, certainly foreign governments have no oversight capability in regards to this data.
This, I think, is enormous. I suspect our allies already knew about the program. We probably told them, but just because allied governments were advised, that does not mean that their citizens knew anything about it. Now they do. I have no idea what will happen as a result, but I think this is a very, very delicate time for the United States and for the world.
Just food for thought.