Earlier quoted context omitted.
They don't seem to be handling this very intelligently, more like a bully than anything else. It would be much easier to let Snowden get to a country in southamerica and then after some weeks press under the table to get him arrested. Now doing all this pressing all they get is Snowden in China or Russia's arms.
If you assume the goal of all this is to deter future leaks, I'd say they are doing a pretty good job. Snowden has so much uncertainty and risk in the next few weeks that I bet borderline whistle-blowers are rethinking their plan. Arresting him quietly without the media gets them Snowden, but not the deterrent.
Whistle-blowers may be releasing information because of strong ethical objections, not rational thoughts about their own well-being.
I think watching this unfold with obvious lies from governments has actually strengthened the ethics in releasing this information, and may reinforce others with similar information that leaking really is the morally right thing to do.